Neuroblastoma, Susceptibility To, 1
A number sign (#) is used with this entry because of evidence that susceptibility to neuroblastoma-1 (NBLST1) is conferred by germline and somatic mutations in the KIF1B gene (605995) on chromosome 1p36.
DescriptionNeuroblastoma is the most common childhood cancer diagnosed before the age of 1 year, and accounts for 10 to 15% of all cancer deaths in children. Some patients inherit a genetic predisposition to neuroblastoma due to germline mutations, whereas others develop sporadic disease that may result from either germline or somatic mutations. Neuroblastoma tumors are derived from embryonic cells that form the primitive neural crest and give rise to the adrenal medulla and the sympathetic nervous system (Roberts et al., 1998; Eng, 2008). Histopathologically, neuroblastoma can range in type from the most aggressive form, neuroblastoma, composed entirely of immature neural precursor cells, to ganglioneuroma, composed entirely of mature neural tissue. The most important prognostic factor for patients with neuroblastoma is the extent of the tumor at the time of diagnosis (Roberts et al., 1998).
Neuroblastoma can also be part of cancer-prone syndromes, such as paragangliomas (see, e.g., PGL4; 115310).
Genetic Heterogeneity of Susceptibility to Neuroblastoma
Susceptibility to neuroblastoma is genetically heterogeneous and is conferred by mutation in the PHOX2B gene (603851) on chromosome 4p12 (NBLST2; 613013) and by mutation in the ALK gene (105590) on chromosome 2p23 (NBLST3; 613014).
Loci implicated in the development of neuroblastoma include 6p (NBLST4; 613015), 2q35 (NBLST5; 613016), and 1q21 (NBLST6; 613017).
Clinical FeaturesEarly Familial Reports
Dodge and Benner (1945) reported a brother and sister with neuroblastoma of the adrenal medulla. In the family of Zimmerman (1951), the father had had a mediastinal ganglioneuroma removed at age 10 years. Helson et al. (1969) found elevated catecholamines in sibs of children with overt neuroblastomas. Chatten and Voorhees (1967) reported a kindred with multiple disorders, including neuroblastomas in 4 sibs. All also had cafe-au-lait spots. Gerson et al. (1974) gave a follow-up on the family reported by Chatten and Voorhees (1967). The mother of 4 sibs with neuroblastoma had persistently elevated urinary catecholamines, but was asymptomatic. She was subsequently found to have a posterior mediastinal mass which in retrospective review of radiographs was found to have been present and of constant size for at least 16 years. Griffin and Bolande (1969) described 2 sisters with congenital disseminated neuroblastoma. Both had regression of the retroperitoneal tumors to fibrocalcific residues and maturation to ganglioneuroma. In 1, metastatic nodules in the skin matured to ganglioneuromas and came to resemble neurofibromas by progressive loss of ganglion cells. A 15-year-old sister had a small focus of adrenal calcification on x-ray.
Wong et al. (1971) described an affected brother and sister, each of whom was diagnosed at the age of 5.5 months. The father showed increased amounts of vanillylmandelic acid in the urine. Hardy and Nesbit (1972) reported neuroblastoma in a brother and sister and a male first cousin. Wagget et al. (1973) described 2 sib pairs of which all 4 died with metastatic neuroblastoma. There was no evidence of tumor or neurofibromatosis in sibs or parents.
Pegelow et al. (1975) reported a family with 3 instances of neuroblastoma. The proposita had neuroblastoma at birth and both parents had had children, by previous matings, who had died of neuroblastoma. Hecht et al. (1982) reported further information on the family reported by Pegelow et al. (1975). The proposita was well at age 8.5 years, after receiving chemotherapy early in life. By the previous marriage, the father of the proposita had a healthy son who fathered a child with congenital metastatic neuroblastoma. Two chromosomal variants were segregating in the family, but neither correlated with neuroblastoma or the presumed carrier status.
Other FeaturesWilson et al. (2002) reported a 6-month-old girl with congenital and progressively increasing proptosis due to an orbital mass that caused no osseous destruction. After complete excision, histopathologic examination revealed an orbital teratoma which contained an area of neuroblastoma. The child was followed up for 2 years and had no evidence of recurrent orbital tumor or neuroblastoma at other sites. Wilson et al. (2002) concluded that orbital teratomas may rarely contain non-germ cell malignancies and advised that initial clinical management should begin with complete excision.
InheritancePlon (1997) reported a family in which 2 sibs and a second cousin had the diagnosis of neuroblastoma at less than 1 year of age. The father of the sibs had had Wilms tumor (194070) in childhood, but neither the grandparents nor the great-grandparents of the affected children were known to be affected. There was no history of consanguinity. Plon (1997) suggested that the pattern of inheritance may indicate anticipation, and referred to a report by Maris et al. (1996) in which 2 sibs and a second cousin had neuroblastoma. Maris et al. (1996) also reported another family with 2 affected half-sibs and an unaffected mother. Plon (1997) noted that in the classic study of the genetics of neuroblastoma, Knudson and Strong (1972) referred to 13 instances of multiple occurrences within a family. In 1 family, 2 second cousins were affected. The remainder of the 12 families had multiple affected sibs, including 1 half-sib pair. Taken together, these reports suggested that unaffected adults may transmit a predisposition to the development of neuroblastoma to their offspring. Knudson and Strong (1972) also concluded that the age at onset of neuroblastoma in familial versus sporadic cases was consistent with a 2-hit mechanism and that autosomal recessive inheritance is unlikely.
DiagnosisScreening for neuroblastoma using the detection of catecholamines in the urine was performed in 92% of the 476,654 children born in the province of Quebec during a 5-year period, 1989 to 1994 (Woods et al., 2002). The conclusion was that the program did not seem justified. It appeared to add further weight to a large body of evidence suggesting that neuroblastoma represents at least 2 distinct clinical and biologic entities. Disease with a favorable prognosis is detectable by screening but is associated with a very high rate of spontaneous regression or maturation of neuroblastomas into benign ganglioneuromas. Very few cases of neuroblastoma detected by screening had unfavorable biologic features. Thus, there is a possibility of causing harm by treating cases detected by screening that would otherwise have a benign course. On the other hand, disease with an unfavorable prognosis is rarely detectable by screening and appears not to be affected by the screening procedure as a general public health intervention. Woods et al. (2002) suggested that in Japan, where screening for neuroblastoma is mandatory, this policy should be reconsidered.
Schilling et al. (2002) reported a urine screening program for neuroblastoma at 1 year of age in 1,475,773 children in Germany. The results were similar to those in Quebec; the findings did not support the usefulness of general screening for neuroblastoma at 1 year of age.
PathogenesisBeckwith and Perrin (1963) stated that microscopic foci of neuroblastoma in the adrenals have an incidence of about 1 in 200 during infancy. They suggested that heterozygotes for a 'neuroblastoma gene' may have only neuroblastoma in situ.
Perucho et al. (1981) found that DNA from a neuroblastoma cell line contained a transforming element, i.e., one that would transform mouse fibroblasts which became thereby tumorigenic in nude mice.
Neuroblastoma at times shows spontaneous regression. Particularly dramatic are cases of disseminated disease involving the liver, skin, and bone marrow, which are labeled Stage IV-S (4S) to differentiate them from the more usual, fatal disseminated form, Stage IV. Knudson and Meadows (1980) postulated that neuroblastoma IV-S represents a hereditary one-hit neoplastic disorder of multicellular origin in which nonmalignant neural crest cells bear a mutation that interferes with their normal differentiation. Delayed maturation may ultimately transform them into ganglioneuromas or neurofibromas.
Shimizu et al. (1983) demonstrated that DNA from a human neuroblastoma cell line was capable of inducing foci of transformed NIH 3T3 cells after DNA-mediated gene transfer. Human sequences responsible for the transformation were isolated from the mouse cells and were shown to be present in all human cells. No gross rearrangement was demonstrable in the sequences in the neuroblastoma cell line. Shimizu et al. (1983) demonstrated a transforming gene in a neuroblastoma cell line that was related to both KRAS (190070) and HRAS (190020) and probably codes for an immunologically cross-reactive and structurally related protein, which they termed NRAS (164790). Preliminary results suggested that the transforming gene identified by Shimizu et al. (1983) (NRAS) was situated on chromosome 1 (Ryan et al., 1983).
For a discussion of the amplification and overexpression of the MYCN oncogene in neuroblastoma, see 164840.
Stupack et al. (2006) showed that suppression of caspase-8 (601763) expression occurs during the establishment of neuroblastoma metastases in vivo, and that reconstitution of caspase-8 expression in deficient neuroblastoma cells suppressed their metastases. Caspase-8 status was not a predictor of primary tumor growth; rather, caspase-8 selectively potentiated apoptosis in neuroblastoma cells invading the collagenous stroma at the tumor margin. Apoptosis was initiated by unligated integrins (see 605025) by means of a process known as integrin-mediated death. Loss of caspase-8 or integrin rendered the cells refractory to integrin-mediated death, allowed cellular survival in the stromal microenvironment, and promoted metastases. Stupack et al. (2006) concluded that these findings define caspase-8 as a metastasis suppressor gene that, together with integrins, regulates the survival and invasive capacity of neuroblastoma cells.
Swarbrick et al. (2010) found that 203 (99%) of 205 neuroblastoma samples expressed a mature microRNA from the 5-prime end of MIR380 (613654) called MIR380-5p, which negatively regulates p53 (TP53; 191170) expression. Substantial overexpression of MIR380-5p was found in 76% of these tumors compared to normal brain tissue. High expression correlated with poor outcome in MYCN-amplified neuroblastoma. Inhibition of MIR380-5p in neuroblastoma cells resulted in induction of p53 and extensive apoptotic tumor cell death, and treatment of an orthotopic mouse model of neuroblastoma with a MIR380-5p antagonist resulted in decreased tumor size. These results suggested a novel therapeutic approach to reactivate p53 in neuroblastoma.
In MYCN-amplified neuroblastoma cell lines, Powers et al. (2016) showed that LIN28B (611044) is dispensable, despite derepression of the LET7 miRNA (see 605386). Powers et al. (2016) demonstrated that MYCN mRNA levels in amplified disease are exceptionally high and sufficient to sponge LET7, which reconciles the dispensability of LIN28B. The authors found that genetic loss of LET7 is common in neuroblastoma, inversely associated with MYCN amplification, and independently associated with poor outcomes, providing a rationale for chromosomal loss patterns in neuroblastoma. Powers et al. (2016) proposed that LET7 disruption by LIN28B, MYCN sponging, or genetic loss is a unifying mechanism of neuroblastoma development with broad implications for cancer pathogenesis.
High-Risk Neuroblastoma
Peifer et al. (2015) performed whole-genome sequencing of 56 neuroblastomas (high-risk, n = 39; low-risk, n = 17) and discovered recurrent genomic rearrangements affecting a chromosomal region at 5p15.33 proximal to TERT (187270). These rearrangements occurred only in high-risk neuroblastomas (12/39, 31%) in a mutually exclusive fashion with MYCN (164840) amplifications and ATRX (300032) mutations, which are known genetic events in this tumor type. In an extended case series (n = 217), TERT rearrangements defined a subgroup of high-risk tumors with particularly poor outcome. Despite the high structural diversity of these rearrangements, they all induced massive transcriptional upregulation of TERT. In the remaining high-risk tumors, TERT expression was also elevated in MYCN-amplified tumors, whereas alternative lengthening of telomeres was present in neuroblastomas without TERT or MYCN alterations, suggesting that telomere lengthening represents a central mechanism defining this subtype. The 5p15.33 rearrangements juxtapose the TERT coding sequence to strong enhancer elements, resulting in massive chromatin remodeling and DNA methylation of the affected region. Supporting a functional role of TERT, neuroblastoma cell lines bearing rearrangements or amplified MYCN exhibited both upregulated TERT expression and enzymatic telomerase activity. Peifer et al. (2015) concluded that their findings showed that remodeling of the genomic context abrogates transcriptional silencing of TERT in high-risk neuroblastoma and places telomerase activation in the center of transformation in a large fraction of these tumors.
Mechanistic Classification of Neuroblastoma
To investigate the molecular features of divergent neuroblastoma subtypes, Ackermann et al. (2018) performed genome sequencing on 416 pretreatment neuroblastomas and assessed telomere maintenance mechanisms in 208 of these tumors. Ackermann et al. (2018) found that patients whose tumors lacked telomere maintenance mechanisms had an excellent prognosis, whereas the prognosis of patients whose tumors harbored telomere maintenance mechanisms was substantially worse. Survival rates were lowest for neuroblastoma patients who were able to maintain telomeres in combination with RAS and/or p53 pathway mutations. Spontaneous tumor regression occurred both in the presence and absence of these mutations in patients with telomere maintenance-negative tumors. Ackermann et al. (2018) proposed a mechanistic definition of clinical neuroblastoma subgroups.
CytogeneticsUsing chromosome banding, Balaban-Malenbaum and Gilbert (1977) observed different long nonbanding homogeneously staining regions (HSR) in 4 human neuroblastoma cell lines. The HSR-containing chromosome differed in each line. One line contained 2 classes of cells: one with an HST marker chromosome and the other with double minute chromosomes. The presence of 2 additional chromosomal markers in all cells of this line indicated a common origin.
Brodeur et al. (1977) found a deletion of chromosome 1p in 3 of 6 human neuroblastomas. Gilbert et al. (1981) suggested that chromosome 1p34 contains 1 or more genes responsible for the control of neuroblast proliferation and that the loss of activity of said genes through deletion, rearrangements or point mutations is involved in tumorigenesis in neuroblastoma. This conclusion was based on the finding of chromosomal abnormalities at this site in direct preparations from neuroblastomas or from cell lines. In a human neuroblastoma cell line, Cowell and Rupniak (1983) found a consistent abnormality of 1p: the region distal to 1p31 had homogeneously staining characteristics. Double minutes were also present as a second constitutive feature.
Fong et al. (1989) found that somatic loss of heterozygosity occurred most consistently between 1p36.1 and 1p36.3 in neuroblastomas. They found a correlation between loss of heterozygosity on 1p and amplification of MYCN (164840), which is on chromosome 2p24. Stating that at least 70% of neuroblastomas show cytogenetically visible aberrations in 1p, Weith et al. (1989) presented the results of studies of loss of heterozygosity in 9 different tumors and the corresponding normal tissue. Most of the probes used to detect polymorphic DNA loci were derived from a library of microdissected distal 1p chromosome fragments. Allelic loss was observed with at least 2 probes in 8 of 9 neuroblastomas. The consensus deletion in all 8 tumors included the segment 1p36.2-p36.1. The study of Weith et al. (1989) provided no support for a correlation between 1p deletion and amplification of the MYCN gene in this disorder.
Martinsson et al. (1989) isolated a set of microclones and mapped them on the short arm of chromosome 1. Using some of these, they showed that the breakpoint in a neuroblastoma cell line carrying a translocation involving 1p had a breakpoint at 1p36.1.
Ritke et al. (1989) concluded that the data suggesting that the breakpoints are often located in bands other than 1p32 are in error and that the evidence points to the involvement of specific DNA sequences within 1p32 as important to the development of neuroblastoma. Noting that tumor cells from about 70% of neuroblastoma patients show deletion of part of 1p, they concluded that the abnormality is most likely due to complex translocation and deletion mechanisms. For example, the MYCL locus (164850) is often moved from the altered chromosome 1 to another chromosome. One of the patients in their study had a breakpoint at 1p32 located between JUN (165160) and MYCL, thus establishing the order as centromere--JUN--MYCL--telomere.
Hunt and Tereba (1990) used a panel of 20 cloned sequences and 2 isozymes to determine the location of the breakpoints in 7 neuroblastoma cell lines. They concluded that the most distal deletion breakpoint occurred between MYCL1 and D1S57. They proposed that the neuroblastoma susceptibility gene is located distal to MYCL1, since in 3 of the 5 lines in which MYCL1 was deleted from a chromosome 1, the gene had been translocated to another chromosome, thus retaining the diploid complement. They concluded that another gene linked to MYCL1 may be involved in this neoplasm.
Bader et al. (1991) demonstrated that the reintroduction of chromosome 1 into a human neuroblastoma cell line resulted in differentiation and cell death, consistent with the idea that mutation of a 1p36 gene allows unrestricted growth.
On the basis of loss of heterozygosity (LOH), Takayama et al. (1992) concluded that the commonly deleted region in neuroblastoma is distal to the D1S112 locus, i.e., on 1pter-p36.1. They also found LOH for markers on 14q in 10 out of 25 informative cases (40%). The commonly deleted regions were distal to the D14S13 locus, i.e., on 14q32-qter. Suzuki et al. (1989) had found frequent loss of heterozygosity on chromosome 14q.
Biegel et al. (1993) reported a child with dysmorphic features, as well as developmental and growth delay, who developed neuroblastoma at 5 months of age. Cytogenetic analysis of blood lymphocytes demonstrated an interstitial deletion of 1p36.2-p36.1, which was apparent only with high-resolution banding. The interstitial deletion involving subbands of 1p36 was corroborated by molecular analysis with a collection of polymorphic DNA probes for 1p.
Caron et al. (1993) reported that allelic loss of 1p36 was found in 15 of 53 neuroblastomas; in 13 of the 15, the lost allele was of maternal origin. Cheng et al. (1993) found that the paternal allele was lost from 1p in 6 of 10 cases, consistent with a random distribution. Cheng et al. (1993) also found that the paternal allele of N-myc (MYCN; 164840) was preferentially amplified in 12 of 13 cases of neuroblastoma.
Caron et al. (1994) described 3 neuroblastoma tumors and 2 cell lines in which LOH in 1p resulted from an unbalanced translocation between the short arm of chromosome 1 and the long arm of chromosome 17. Southern blot and cytogenetic analyses showed that in all cases the chromosome 17 homolog from which the 1;17 translocation was derived was still present and intact. This suggested a model in which a translocation between the short arm of chromosome 1 and the long arm of chromosome 17 takes place in the S/G2 phase of the cell cycle and results in LOH 1p. Nonhomologous mitotic recombination in the S/G2 phase had not previously been observed as a mechanism of LOH.
Caron et al. (1995) examined the question of genomic imprinting of the neuroblastoma tumor suppressor gene on 1p36; previously reported results had been conflicting. They studied the parental origin of 1p36 alleles lost in 47 neuroblastomas. The results were remarkably different for tumors with and without amplification of the N-myc oncogene. In the N-myc single-copy tumors, they found that the lost 1p36 alleles were preferentially of maternal origin (16 of 17 cases) and that the commonly deleted region mapped to 1p36.3-p36.2. In contrast, all N-myc-amplified neuroblastomas had larger 1p deletions, extending from the telomere to at least 1p36.1-p35. These deletions were of random parental origin (18 of 30 maternal LOH). This strongly suggested that different suppressor genes on 1p are inactivated in these 2 types of neuroblastoma. Deletion of a more proximal suppressor gene is associated with N-myc amplification, while a distal, probably imprinted, suppressor can be deleted in N-myc single-copy cases.
To characterize the region of consistent deletion of 1p in neuroblastoma, White et al. (1995) performed LOH studies on 122 neuroblastoma tumor samples using 30 distal chromosome 1p polymorphisms. LOH was detected in 32 of the 122 tumors (26%). A single region of LOH, marked distally by D1Z2 and proximally by D1S228, was deleted in all tumors demonstrating loss. Also, cells from a patient with a constitutional deletion of 1p36 and from a neuroblastoma cell line with a small 1p36 deletion were analyzed by fluorescence in situ hybridization. Cells from both sources had interstitial deletions of 1p36.3-p36.2 that overlapped the consensus region of LOH defined by the tumors. Four proposed candidate genes--DAN (600613), ID3 (600277), CDC2L1 (176873), and TNFR2 (191191)--were shown to lie outside the consensus region of allelic LOH, as defined by the above deletions. These results more precisely defined the location of the neuroblastoma suppressor gene within 1p36.3-p36.2, eliminating 33 cM of proximal 1p36 from consideration. Furthermore, a consensus region of loss that excluded the 4 leading candidate genes was found in all tumors with 1p36 LOH.
Mead and Cowell (1995) identified a constitutional t(1;10)(p22;q21) translocation in a child with stage 4S neuroblastoma. Stage 4S neuroblastoma is a specific type that occurs mainly in children under the age of 1 year and is defined as a small stage 1 or 2 primary tumor, but with a very particular pattern of metastatic disease. Metastatic deposits can be found in the skin, presenting as bluish lumps, in the bone marrow, where they form only a small proportion of the nucleated cells, and, most significantly, in the liver, with huge homogeneous involvement. The special feature of stage 4S neuroblastoma is that, despite the metastatic spread and the massive liver involvement, the tumor has the capacity to regress spontaneously. This observation led D'Angio et al. (1971) to suggest that stage 4S represents a transient failure in differentiation. However, some stage 4S tumors, after an initial spontaneous regression, recur as a high-grade malignancy and proceed to kill the patient (Roberts et al., 1998). Roberts et al. (1998) cloned the breakpoints of the translocation in the patient reported by Mead and Cowell (1995) and identified 2 genes that were fused in-frame to generate a novel gene. The 1p22 gene, which they called NB4S (EVI5; 602942), encodes a protein with a 200-amino acid region that shares homology with TBC1 box motif genes involved in cell growth and differentiation. The chromosome 10 breakpoint interrupted a novel transcript, called TRNG10, that could only be detected in tumor cells. This transcript has no exon/intron structure or significant open reading frame, suggesting that it is a structural RNA that is transcribed but not translated. The chromosome rearrangement created a fusion gene product that combined the TBC1 motif of NB4S with a polyadenylation signal from TRNG10, potentially generating a truncated protein with oncogenic properties.
Lo Cunsolo et al. (1999) described a sibship in which 1 child had disseminated (stage 4) neuroblastoma and another had a localized (stage 2) neuroblastoma. By using double-color fluorescence in situ hybridization, they observed that the subtelomeric locus D1Z2, located at 1p36, was deleted in the tumors of both patients. The MYCN gene was found in single copy in both tumors. Loss of heterozygosity and RFLP analyses detected somatic LOH at D1S468 (in 1p36) in a tumor cell population with a trisomy of chromosome 1 in the stage-2 patient. Neuroblastoma cells of the stage-4 patient were diploid and showed allelic loss at a total of 8 chromosome 1 DNA markers. Haplotype studies showed that the sibs inherited the same paternal 1pter-p36 chromosome region by homologous recombination and that, in the 2 tumors, the 1p arm of different chromosomes of maternal origin was damaged. The results suggested that the sibs inherited the predisposition to neuroblastoma associated with the paternal 1p36 region, and that tumors developed as a consequence of somatic loss of the maternal 1p36 allele.
The loss of heterozygosity at chromosome arms 1p and 11q has frequently been found in neuroblastoma. Attiyeh et al. (2005) performed a systematic screen of 915 samples of neuroblastoma for LOH at 1p36 and 11q23. They found that unbalanced 11q LOH and 1p36 LOH were independently associated with a worse outcome in patients with neuroblastoma.
By analyzing the breakpoints of a t(1;17)(p36.2;q11.2) constitutional translocation in a neuroblastoma patient, followed by PCR of a mammary gland cDNA library, Vandepoele et al. (2005) identified the NBPF1 gene (610501), which was disrupted in this patient.
Molecular GeneticsGermline Mutations in the KIF1B Gene
In 1 pheochromocytoma (171300) and 3 neuroblastoma tumor samples and in corresponding germline DNA samples from the respective patients, Schlisio et al. (2008) identified 4 different missense mutations in the KIF1B gene (605995.0002-605995.0005) on chromosome 1p36.2. The proband with the pheochromocytoma also had neuroblastoma in infancy and a mature ganglioneuroma in adulthood (see 605995.0005). Functional studies in primary rat sympathetic neurons revealed that induction of apoptosis was impaired with all of the KIF1B variants compared to wildtype.
Somatic Mutations
For a discussion of the amplification and overexpression of the MYCN oncogene in neuroblastoma, see 164840.
The et al. (1993) found loss of neurofibromin (NF1; 613113) expression in 3 of 10 human neuroblastoma cells lines. Restriction enzyme analysis indicated that 2 of the lines showed evidence of NF1 mutations.
Whereas reduced expression of NM23 (156490) is associated with a high potential for metastasis in some tumor types, its expression is increased in aggressive neuroblastoma. Chang et al. (1994) identified a somatic ser120-to-gly (S120G) change in 6 of 28 advanced neuroblastomas, but in none of 22 low-grade tumors or in control tissues. They indicated that the mutant enzyme still retained its catalytic activity, but was more susceptible to denaturation.
Abel et al. (2002) presented evidence that the DFFA gene (601882) on chromosome 1p36 is located in the smallest region of deletion overlap in Scandinavian neuroblastoma tumors. They performed genomic sequence analysis of DFFA in 44 primary neuroblastoma tumors and in 2 detected a rare allelic variant in the DFFA gene, i.e., a 206T-C transition in exon 2, resulting in a nonpolar-to-polar substitution (ile69-to-thr; I60T) in a preserved hydrophobic patch of the protein. In 1 tumor, the variant was present in hemizygous form due to deletion of the more common allele, whereas in the other tumor it was present in heterozygous form. Only 1 of 194 normal control alleles was found to carry this variant; thus, none of 97 healthy control individuals was homozygous. Moreover, RT-PCR expression studies showed that the DFFA gene was expressed in low-stage neuroblastoma tumors and to a lesser degree in high-stage neuroblastomas.
Origone et al. (2003) described a child with familial neurofibromatosis I (162200) and disseminated neuroblastoma whose neuroblastoma cells showed homozygous NF1 gene inactivation, MYC amplification, and a chromosome 1p36 deletion. The authors noted that Martinsson et al. (1997) had previously described a patient with NF1 and aggressive neuroblastoma whose tumor cells displayed a large biallelic deletion of the NF1 gene and chromosome 1p36 deletion, but no MYCN amplification.
Molenaar et al. (2012) presented a whole-genome sequence analysis of 87 neuroblastoma of all stages. Few recurrent amino acid-changing mutations were found. In contrast, analysis of structural defects identified a local shredding of chromosomes, known as chromothripsis, in 18% of high-stage neuroblastoma. These tumors are associated with a poor outcome. Structural alterations recurrently affected ODZ3 (610083), PTPRD (601598), and CSMD1 (608397), which are involved in neuronal growth cone stabilization. In addition, ATRX, TIAM1 (600687), and a series of regulators of the Rac/Rho pathway were mutated, further implicating defects in neuritogenesis in neuroblastoma. Most tumors with defects in these genes were aggressive high-stage neuroblastomas, but did not carry MYCN (164840) amplifications. Molenaar et al. (2012) concluded that the genomic landscape of neuroblastoma revealed 2 novel molecular defects, chromothripsis and neuritogenesis gene alterations, which frequently occur in high-risk tumors.
Among 71 neuroblastomas, Sausen et al. (2013) identified chromosomal deletions and sequence alterations of the chromatin remodeling genes ARID1A (603024) and ARID1B (614556) in 8 (11%); these were associated with early treatment failure and decreased survival.
Using a combination of whole-exome, genome, and transcriptome sequencing as part of the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) initiative, Pugh et al. (2013) studied 240 individuals with neuroblastoma and reported a low median exonic mutation frequency of 0.60 per Mb (0.48 nonsilent) and notably few recurrently mutated genes in these tumors. Genes with significant somatic mutation frequencies included ALK (105590) (9.2% of cases), PTPN11 (176876) (2.9%), ATRX (300032) (2.5%, and an additional 7.1% had focal deletions), MYCN (1.7%, causing a recurrent P44L alteration), and NRAS (0.83%). Rare, potentially pathogenic germline variants were significantly enriched in ALK, CHEK2 (604373), PINK1 (608309), and BARD1 (601593).
HistoryMorell et al. (1977) noted association between neuroblastoma and an uncommon immunoglobulin Gm phenotype.
Fairchild et al. (1979) described a 29-year-old woman who had neuroblastoma during infancy, developed an extraadrenal pheochromocytoma at age 16 years, with subsequent hepatic recurrence, and was found to have multifocal renal cell carcinoma. Renal cell carcinoma and pheochromocytoma are combined in the von Hippel-Lindau syndrome (VHL; 193300), but there was no evidence in this patient or her family. The association of pheochromocytoma and neuroblastoma had, it seemed, not been previously noted. Schimke et al. (2010) reported 2 sibs of the patient reported by Fairchild et al. (1979) who developed paraspinal paragangliomas in adulthood, and a cousin of these sibs who died of metastatic renal cell carcinoma and had a history of a benign paraaortic paraganglioma. Genetic analysis identified a heterozygous mutation in the SDHB gene (V140F; 185470.0016), consistent with paragangliomas-4 (PGL4; 115310). There were 2 unaffected family members, suggesting decreased penetrance or a 'leaky' mutation. Schimke et al. (2010) noted the importance of family history in elucidating the etiology of this inherited disorder.