Basal Cell Nevus Syndrome

A number sign (#) is used with this entry because basal cell nevus syndrome (BCNS) can be caused by mutations in the PTCH1 gene (601309) on chromosome 9q22, the PTCH2 gene (603673) on 1p32, or the SUFU gene (607035) on 10q24-q25.

Somatic mutations in the PTCH2 gene have been identified in basal cell carcinoma (605462) and in medulloblastoma (155255), both of which are features of the nevoid basal cell carcinoma syndrome.

Clinical Features

Gorlin and Goltz (1960) described a familial syndrome comprising multiple nevoid basal-cell epitheliomas, jaw cysts, and bifid rib. Inheritance was autosomal dominant.

Herzberg and Wiskemann (1963) described what they termed the 'fifth phakomatosis,' basal cell nevus syndrome with medulloblastoma. They reported a family in which both father and son had basal cell nevi, with the son also having medulloblastoma and congenital thoracic scoliosis. Cawson and Kerr (1964) described a syndrome of jaw cysts, basal cell tumors, and skeletal abnormalities. One of the patients had astrocytoma with severe hydrocephalus. Other features included pits of the palms and soles. Lile et al. (1968) observed 4 cases in 3 generations of a family. Two of the patients had a short terminal phalanx of the thumb.

Berlin et al. (1966) observed ovarian carcinoma in association with this syndrome. Huge calcified ovarian fibromas were present in a clinicopathologic conference (CPC) case discussed by Holmes (1976) at the Massachusetts General Hospital. The occurrence of lymphomesenteric cysts, described by Clendenning et al. (1963), was emphasized in another CPC case by Ottinger and Vickery (1986).

Holubar et al. (1970) found basal cell epitheliomas in multiple palmar pits in an 8-year-old girl with BCNS. Schwartz (1978) noted hamartomatous polyps of the stomach and mesenteric cysts as features of the basal cell nevus syndrome. Totten (1980) observed a large congenital lung cyst occupying the left thoracic cavity in an affected patient.

Cramer and Niederdellmann (1983) described 9 subjects from 3 families with cerebral gigantism syndrome (117550); 7 of the patients also had signs of the basal cell nevus syndrome. In 1 family, a father was 193 cm tall at age 45 and his son was 197 cm tall at age 18; both had jaw cysts and other signs of basal cell nevus syndrome. Another son was 198 cm tall at age 17 years. Macrocephaly, mild hydrocephalus, intracranial calcification, and EEG abnormalities were also described.

McKusick (1985) observed unilateral coloboma of the iris and glaucoma in a patient with BCNS. Levine et al. (1987) described subconjunctival epithelial cysts presenting a dramatic appearance of everted upper eyelids in patients with this condition.

De Jong et al. (1985) described 4 patients with Gorlin syndrome, 1 of whom had been reported as case 2 by Hermans et al. (1965), who all exhibited prominent medullated retinal nerve fibers, either unilaterally or bilaterally. The authors stated that review of the literature revealed 4 more patients with Gorlin syndrome and medullated retinal nerve fibers (Anderson et al., 1967; Cernea et al., 1969; Hammami et al., 1976; Poissonnet et al., 1977). De Jong et al. (1985) concluded that medullated retinal nerve fibers represent an additional ophthalmologic manifestation of Gorlin syndrome.

Jones et al. (1986) reported a woman with Gorlin syndrome who underwent cardiac transplantation for an unresectable fibrous histiocytoma of the left ventricle at age 19 years (Jamieson et al., 1981). She had a marfanoid habitus, frontal bossing with large occipitofrontal circumference, ocular hypertelorism, broad nasal root, enlarged jaw, glaucoma, long fingers, multiple odontogenic keratocysts, postaxial polydactyly of right foot, and bony bridging of right metatarsals 4 and 5.

Evans et al. (1991) found abnormal ribs in 2 infants delivered preterm at 29 and 25 weeks. The finding at first was thought unimportant but subsequently was shown to indicate that some members of their families had Gorlin syndrome. In the first case, early routine chest radiographs showed an incidental finding of bifid ribs. The 25-year-old father had a dislocated shoulder from birth due to Sprengel deformity (184400), pronounced frontal bossing with enlarged head, hypertelorism, calcification of the falx cerebri, pituitary fossa totally bridged by bone, and bilateral bifid ribs. A 5-year-old brother had calcifications within the falx cerebri. A 4-year-old brother had been diagnosed as having arrested congenital hydrocephalus, and chest radiograph showed 2 bifid ribs. The second index patient had possible Sprengel deformity in addition to bifid ribs. This patient's mother had had 5 jaw cysts removed between ages 11 and 31. She also had an enlarged head with pronounced frontal bossing, pits in the palms of her hands and feet, multiple milia on her forehead, and hypertelorism. Radiographs showed scoliosis, calcified ovarian fibroma, calcification of the falx cerebri, and minor rib anomalies.

Evans et al. (1993) reported the clinical complications of this disorder in 84 patients. Basal cell carcinomas and jaw cysts occurred in more than 90% of patients by 40 years of age, but both sometimes occurred before 10 years of age. Less well-described complications included ovarian calcification or fibroma (24%), medulloblastoma (5%), cardiac fibroma (3%), cleft palate (5%), and ophthalmic abnormalities such as squint or cataract (26%). Shanley et al. (1994) identified 118 cases in Australia. The frequency of most manifestations were similar to those reported by Evans et al. (1993). A major difference, however, was that the multiple basal cell carcinomas were manifest from an earlier age in the Australian population, which was considered to reflect greater exposure to ultraviolet radiation. Of the 64 families ascertained, 37 represented sporadic cases, and accordingly the new mutation rate appeared to be high. Multiple BCCs occurred before age 20 years in 90 (75%) of 118 cases.

Goldstein et al. (1994) examined 11 African Americans from 2 families with Gorlin syndrome, which they abbreviated 'NBCC' for nevoid basal cell carcinoma syndrome. They also reviewed the literature on this condition in African Americans. African Americans tended to have reduced expression of the basal cell carcinomas but full expression of other syndrome components. The 3 most common findings in their 11 cases were jaw cysts, palmar and/or plantar pits, and calcification of the falx cerebri. Only 4 of the 11 had 1 or more confirmed basal cell carcinomas, whereas the frequency of basal cell carcinomas in whites had been estimated at 90%.

Kimonis et al. (1997) reviewed the findings in 105 individuals with Gorlin syndrome examined at the NIH since 1985. The data derived from 48 males and 57 females ranging in age from 4 months to 87 years. They found that 80% of whites (71 of 90) and 38% of African Americans (5 of 13) had at least 1 basal cell carcinoma, with the first tumor occurring at a mean age of 23 and 21 years, respectively. Excluding individuals exposed to radiation therapy, the number of BCCs ranged from 1 to more than 1,000, and 1 to 3, respectively, in the 2 ethnic groups. Other features included jaw cysts (74%), palmar pits and plantar pits (87%), and ovarian fibromas (17%). Medulloblastoma occurred in 4 patients at a mean age of 2.3 years. Three patients had cleft lip or palate. Physical findings included coarse facies (54%), relative macrocephaly (50%), hypertelorism (42%), frontal bossing (27%), pectus deformity (13%), and Sprengel deformity (11%). Important radiologic signs included calcification of the falx cerebri (65%), of the tentorium cerebelli (20%), bridged sella (68%), bifid ribs (26%), hemivertebrae (15%), fusion of the vertebral bodies (10%), and flame-shaped lucencies of the phalanges, metacarpal, and carpal bones of the hands (30%). Several traits previously considered components of the syndrome, such as short fourth metacarpal, scoliosis, cervical ribs, and spina bifida occulta, were not found to be significantly increased in the affected individuals.

Korczak et al. (1997) reported an African American boy who developed medulloblastoma at age 2 years. He was treated with surgery, chemotherapy, and craniospinal irradiation. He was diagnosed with Gorlin syndrome at age 6 following identification of a large odontogenic keratocyst of the mandible, pits of the palms and soles, and numerous BCCs in the area of the back and neck that had been irradiated previously. Examination of other relatives showed that the mother also had Gorlin syndrome but was more mildly affected; in particular, she had no BCCs. This family illustrated a complex gene-environment interaction. Increased skin pigmentation in African Americans was presumably protective against UV, but not ionizing, radiation. Similar cases in the literature illustrated the importance of considering Gorlin syndrome in the differential diagnosis of any patient who presents with a medulloblastoma, especially before the age of 5 years. Korczak et al. (1997) also concluded that for individuals who are radiosensitive, protocols that utilize chemotherapy in lieu of radiotherapy should be considered.

Hall et al. (1998) reported an 11-year-old African American boy with NBCCS who presented with exotropia and a painful, expanding, cystic mass in the left posterior alveolar ridge. An impacted molar was displaced into the orbit by an odontogenic keratocyst. Further examination revealed palmar and plantar pitting.

Lo Muzio et al. (1999) described the clinical features of Gorlin syndrome in northern Italy. Aside from the many features previously reported, other manifestations included benign dermal cysts, impacted teeth, dental ectopy, exophthalmos, ovarian cysts, and calcification of tentorium cerebelli. The relatively lower percentage of patients with basal cell carcinomas (30%) may have been related to the protective skin pigmentation in the Italian population, as has already been established in African Americans.

Honavar et al. (2001) reviewed 105 consecutive patients with eyelid basal cell carcinoma and found 4 patients with Gorlin-Goltz syndrome, all of whom had a family history of this disorder. Common systemic manifestations included multiple basal cell carcinomas, frontal bossing or increased occipitofrontal circumference, palmar pits, odontogenic keratocyst, ectopic calcification, and bifid ribs. The mean age at detection of the first basal cell carcinoma was 30 years (range, 16-38 years). The eyelid basal cell carcinomas were advanced with orbital infiltration in 3 patients, 1 of whom opted for palliative radiotherapy and 2 of whom underwent orbital exenteration. The fourth patient underwent local reexcision of recurrent basal cell carcinoma with upper eyelid reconstruction. After 41 months' mean follow-up, 3 patients were cured of eyelid basal cell carcinoma and 1 was stable. No patient had life-threatening sequelae of Gorlin-Goltz syndrome. The authors concluded that lifelong monitoring is essential for patient management in Gorlin-Goltz syndrome.

Acrochordons are distinctly uncommon in childhood. Chiritescu and Maloney (2001) evaluated 7 children who presented with pedunculated papules (acrochordon-like growths). Histopathologic examination of these papules showed basal cell carcinomas in each biopsy specimen. Further physical examination of the subjects and family members confirmed a diagnosis of NBCCS in all 7 children. Chiritescu and Maloney (2001) considered that 'skin tag'-like basal cell carcinomas in childhood may represent a marker for NBCCS and that early diagnosis of this syndrome and early sun protection of the affected children could help decrease the number of lifetime tumors.

Leonardi et al. (2001) reported a patient with NBCCS who had bilateral mandibular coronoid process hyperplasia, a condition that causes a progressive and painless limitation of jaw movements, especially in opening. Leonardi et al. (2002) examined 10 patients with NBCCS for mandibular coronoid process hyperplasia and found that 4 were affected. They suggested that coronoid hyperplasia may be a radiologic criterion for NBCCS and may help in establishing a diagnosis, especially in pediatric patients.

Koch et al. (2002) described a 13-year-old boy with NBCCS who presented with right-sided abdominal pain and was found to have a mesenchymal hepatic tumor. At the age of 3 years he had had treatment of a medulloblastoma by resection and irradiation. The diagnosis of NBCCS was made at the age of 9 on the basis of palmar pits and odontogenic keratocysts of the mandible and maxilla. Multiple basal cell carcinomas developed on his forehead and occipital scalp the following year. The hepatic mass, removed at the age of 13 years, was found to be a mesenchymal tumor of low cellularity, composed of elongated cells embedded in a myxoid matrix. Nuclei were small and elongated, with no nuclear pleomorphism or mitoses. These findings were considered consistent with a benign mesenchymal tumor in the liver. The patient remained asymptomatic without evidence of recurrence at the 18-month follow-up. The mother and older brother were thought to have NBCCS; the paternal grandmother had surgical resection for medulloblastoma, but apparently had no other features of NBCCS. With studies of markers that mapped to the PTCH gene locus at 9q23, loss of heterozygosity in that region was evident in DNA samples from basal cell carcinoma, medulloblastoma, and a mesenchymal hepatic tumor. On the basis of Knudson's 2-hit hypothesis, Koch et al. (2002) concluded that mesenchymal tumors, such as the hepatic fibromyxoid tumor in their patient, may be another complication of NBCCS. They referred to the report by Darling et al. (1997) as another example of benign mesenchymal tumors occurring in another hereditary neoplastic disorder, multiple endocrine neoplasia type I (MEN1; 131100).

Ozturk et al. (2003) reported a mother and daughter with Gorlin syndrome who had calcification of the falx cerebri and tentorium cerebelli and dysgenesis of the corpus callosum and vermis. Vermian dysgenesis was detected in both mother and daughter, suggesting a previously unrecognized finding associated with the disorder.

Fujii et al. (2003) reported a 14-year-old Japanese girl with Gorlin syndrome and ulcerative colitis (see 266600). She had complained of blood stools for 6 months and had exhibited severe scoliosis since infancy. Physical examination revealed multiple nevi, palmar and plantar pits, jaw cysts, and calcification of the falx cerebri, consistent with the diagnosis of Gorlin syndrome. Total colonoscopy revealed an edematous and spotty bleeding mucosa extending from the anus to the transverse colon, and histologic examination was compatible with ulcerative colitis. Fujii et al. (2003) noted that Katz et al. (1968) and Sawyer and Braverman (1969) had also reported Gorlin syndrome associated with inflammatory bowel disease.

Wilson et al. (2006) reported on the occurrence of discrete patches of unusually long pigmented hair on the skin of 3 patients with Gorlin syndrome from 2 unrelated families with confirmed heterozygous PTCH1 mutation. The SHH (600725)-PTCH1 pathway is known to play an important role in the formation and cycling of hair follicles. Wilson et al. (2006) suggested that these discrete patches of hair represented genuine physical signs associated with Gorlin syndrome and discussed molecular mechanisms by which they might arise.

Kimonis et al. (2013) studied minor and major clinical features in 30 children and teenagers and compared the findings with 75 adults from 26 families with nevoid basal cell carcinoma syndrome. Fifty percent of children/teenagers and 82% of adults had at least one basal cell carcinoma. Jaw cysts occurred in 60% of children/teenagers and 81% of adults. Palmar/plantar pits were the most frequent feature seen in affected individuals at all ages. Macrocephaly was seen in 50% of affected and 8% of unaffected children/teenagers. Frontal bossing, hypertelorism, Sprengel deformity, pectus deformity, and cleft lip/palate were seen among affected children/teenagers but not among their unaffected sibs. Falx calcification was seen in 37% of individuals under 20 and 79% of those over 20 years of age. Kimonis et al. (2013) suggested evaluation for palmar/plantar pits, craniofacial features, and radiologic manifestations to permit early diagnosis and optimum surveillance of nevoid basal cell carcinoma syndrome.

Fujii et al. (2013) reported a 13-year-old Japanese girl with NBCCS and a germline mutation in the PTCH2 gene. At 10 years of age, she had multiple keratocystic odontogenic tumors surgically removed. At age 12, she exhibited proteinuria and was diagnosed with chronic glomerular nephritis. She had normal intelligence and exhibited no structural abnormalities of face, oral cavity, or limbs. Chest x-ray revealed left bifid rib without any other bone abnormalities. She had no other features of NBCCS. Fujii et al. (2013) suggested that patients with PTCH2 mutations may have a milder phenotype than patients with PTCH1 mutations.

Inheritance

About 40% of cases represent a de novo mutation (Gorlin, 1982). Jones et al. (1975) found evidence of paternal age effect in new mutations for this disorder.

Diagnosis

Kimonis et al. (1997) tabulated major and minor criteria that could be used in making the diagnosis of Gorlin syndrome by the presence of 2 major or 1 major and 2 minor criteria. They suggested that a child who is at risk for having inherited the gene should have careful physical examination at birth for pits and other minor features and radiologic evaluation with rib, skull, and spine films to look for skeletal abnormalities. In their study, the risk of developing a medulloblastoma was greatest between 2 and 3 years; however, such had been reported up to age 7 years (Evans et al., 1991). Kimonis et al. (1997) suggested that advising patients to reduce exposure to UV radiation may lessen their risk of developing BCCs. Radiation therapy should also be avoided, but this is understandably difficult when there is a need to make the diagnosis and provide for proper surveillance.

Prenatal Diagnosis

Bialer et al. (1994) made the prenatal diagnosis of Gorlin syndrome in a pregnancy sired by a man with Gorlin syndrome. There were 2 other affected members in the family. Polymorphic DNA markers on chromosome 9 were used and the fetal diagnosis was confirmed by ultrasound scan which showed unilateral cleft lip, probable cleft palate, and hydrocephalus. The parents elected to terminate the pregnancy and examination of the fetus revealed aqueductal stenosis, cleft lip, and cleft palate with a prominent forehead and macrocephaly.

Mapping

By linkage analysis, Farndon et al. (1992) localized BCNS to chromosome 9q22.3-q31 (maximum lod scores of 3.597 and 6.457 at markers D9S12 and D9S53). Reis et al. (1992) confirmed the assignment to chromosome 9 and concluded that D9S43 is centromeric to BCNS and that GSN (137350) and ASS (603470) are telomeric to BCNS.

In their collection of Australasian pedigrees, Wicking et al. (1994) further refined the localization of the BCNS gene to a 2-cM interval between D9S196 and D9S180. Farndon et al. (1994) concluded that the gene involved with NBCCS lies in a 2.6-cM interval centromeric to D9S287. Recombinants also mapped the gene for Fanconi anemia, group C (FANCC; 227645) to the same region (maximum lod score of 5.601).

Cytogenetics

Gibbs et al. (1986) found no chromosomal abnormalities in 6 BCNS patients from 4 families.

Gailani et al. (1992) found allelic loss in the chromosome 9q31 region in 11 of 16 sporadic basal cell carcinomas, in 2 hereditary basal cell carcinomas, and in 1 hereditary ovarian fibroma. Furthermore, in a study of 5 Gorlin syndrome kindreds, tight linkage was found with a genetic marker in this region.

Among 15 Australasian pedigrees, Chenevix-Trench et al. (1993) demonstrated that the NBCCS gene was linked to markers in the same region of chromosome 9 with no evidence of significant heterogeneity. Loss of heterozygosity (LOH) was detected in half of sporadic cases of basal cell carcinoma, a rate significantly higher than that in other skin lesions used as controls. These findings suggested that sporadic basal cell carcinomas may be due to mutation in the same gene.

Shimkets et al. (1996) reported cytogenetic and molecular characterization of germline deletions in a patient with a chromosome 9q22 deletion and a second patient with a deletion of 9q22-q31. Both had typical features of Gorlin syndrome plus additional findings. Shimkets et al. (1996) noted that the fact that Gorlin syndrome can be caused by null mutations provided evidence that associated neoplasms arise with homozygous inactivation of the gene.

Midro et al. (2004) described an 11-year-old girl with an interstitial deletion of 9q22.32-q33.2 associated with a familial translocation t(9;17)(q34.11;p11.2) who had clinical features consistent with basal cell nevus syndrome and some features of nail-patella syndrome (NPS; 161200). The translocation breakpoint on 9q34.11 mapped proximal to the ABL gene (189980), between the BAC clone RP11-88G17 and the LMX1B gene (602575), which is mutated in nail-patella syndrome.

Molecular Genetics

PTCH1 Gene

In 2 unrelated patients with Gorlin syndrome, Johnson et al. (1996) identified 2 different heterozygous mutations in the PTCH1 gene (601309.0001 and 601309.0002, respectively). Johnson et al. (1996) stated that PTCH1 is expressed in developing sclerotome, branchial arches, limbs, and spinal cord and in vertebrate skin and noted that the pattern of vertebrate gene expression was consistent with the abnormalities found in BCNS.

Simultaneously and independently, Hahn et al. (1996) isolated a identified PTCH1 mutations in unrelated patients with BCNS (see, e.g., 601309.0003-601309.0005). The authors proposed that a reduction in the expression of the PTCH1 gene can lead to the developmental abnormalities observed in this syndrome and that complete loss of PTCH1 function contributes to the transformation of certain cell types. Two sporadic basal-cell carcinomas with allelic loss of the NBCCS region had inactivating PTCH1 mutations in the remaining allele.

Fujii et al. (2003) identified a mutation in exon 9 of the PTCH1 gene (601309.0016) in a 14-year-old Japanese girl with Gorlin syndrome and ulcerative colitis.

Takahashi et al. (2009) identified 6 different heterozygous truncating germline mutations in the PTCH1 gene in 6 Japanese families with BCNS. There was no evidence of a founder effect.

PTCH2 Gene

Using combined single-strand conformation polymorphism (SSCP) and heteroduplex analysis, Smyth et al. (1999) identified somatic mutations in the PTCH2 gene (603673.0001 and 603673.0002) in a medulloblastoma and basal cell carcinoma, respectively.

In affected members of a Chinese Han family with BCNS, Fan et al. (2008) identified a heterozygous germline mutation in the PTCH2 gene (603673.0003).

In a 13-year-old Japanese girl who was diagnosed with NBCCS based on multiple keratocystic odontogenic tumors and a left bifid rib and who was found to have no mutations in the PTCH1 or SUFU genes, Fujii et al. (2013) identified heterozygosity for a frameshift mutation (603673.0004) in the PTCH2 gene.

SUFU Gene

In a family exhibiting atypical signs and symptoms of Gorlin syndrome, in which the 4.5-year-old proband had palmar and plantar pits, macrocrania, and medulloblastoma, and his 37-year-old father had plantar pits, calcification of the falx and macrocrania, Pastorino et al. (2009), analyzed the PTCH1 gene but found no mutations. Analysis of the SUFU gene (607035), which like PTCH1 and PTCH2 is a component of the SHH (600725) signaling pathway, revealed a splice site mutation (607035.0003) in the proband and his father. The clinically unaffected paternal grandparents were negative for the mutation, suggesting that it arose de novo in the father.

Pathogenesis

Patients with BCNS are abnormally sensitive to radiotherapeutic doses of ionizing radiation; several treated patients have developed an unusually large number of basal cell tumors in the irradiated area a short time after exposure. However, Featherstone et al. (1983) did not detect radiosensitivity at the cellular level.

Levanat et al. (1996) suggested a 2-hit mechanism for neoplasia in the Gorlin syndrome according to the Knudson model. The authors concluded that the causative gene probably functions as a tumor suppressor based on deletion of the relevant region of 9q found in many neoplasms occurring in the syndrome. Some of the associated developmental defects may also arise through a 2-hit mechanism. Like neoplasms in familial cancer predisposition syndromes, the jaw cysts in Gorlin syndrome are multiple and appear in a random pattern, but similar defects are seen occasionally as an isolated finding in the general population. Levanat et al. (1996) examined a series of chromosome 9 polymorphisms in abnormal and matched constitutional tissue and found that the lining of the jaw cysts lost the normal copy of the Gorlin syndrome region while retaining the mutant copy. These results suggested to them that a somatic mutation of a particular gene in an embryonic or fetal cell leads to abnormal migration, or differentiation, or perhaps failure to undergo programmed cell death, manifested later as a developmental defect.

Genotype/Phenotype Correlations

Wicking et al. (1997) screened 71 unrelated individuals with NBCCS for mutations in the PTCH exons. They identified 28 mutations that were distributed throughout the entire gene and predicted that 86% would cause protein truncation. Wicking et al. (1997) identified 3 families bearing identical genotypes with variable phenotypes. From this they concluded that phenotypic variability in NBCCS is a complex genetic event. No phenotype/genotype correlation between the position of the truncation mutations and major clinical features was evident. Wicking et al. (1997) concluded that the preponderance of truncation mutations in the germline of NBCCS patients suggests that the developmental defects associated with NBCCS are likely due to haploinsufficiency.

Bale (1997) reviewed factors contributing to the variable expressivity of PTCH mutations in NBCCS. He reported that clinical features of NBCCS syndrome differ more among families than within families. Shimkets et al. (1996) reported 2 patients with small interstitial deletions on chromosome 9q which involved the PTCH gene. Phenotypes of the 2 patients differed with respect to several key findings (e.g., occurrence of jaw cysts, palmar pits, and skeletal abnormalities). Bale (1997) noted that developmental defects may also arise through a 2-hit mechanism and he reviewed evidence for loss of the normal allele in epithelial cells lining jaw cysts. Bale (1997) noted the absence of genotype/phenotype correlations in NBCCS and concluded that modifying genes and germline variants resulting in hypomorphic or hypermorphic alleles may play an important role in determining the phenotype.

Population Genetics

Farndon et al. (1992) estimated that the minimum prevalence of basal cell nevus syndrome is 1 per 57,000; 1 in 200 patients with basal cell carcinomas had the syndrome, but the proportion was much higher among those in whom a basal cell carcinoma developed before age 19. Only a few of the nevi grew and became locally invasive, and basal cell carcinomas did not develop at all in about 15% of affected persons. In some cases, radiation treatment resulted in fresh crops of aggressive basal cell carcinomas and led to severe disfigurement.

History

Although Gorlin has described many syndromes, several of which have been given his name, none is more intimately connected with his name than the basal cell nevus syndrome. See Gorlin (1993) for an autobiography.

Multiple basal cell naevus syndrome was described in ancient Egypt (Satinoff and Wells, 1969).

Loose linkage to Rh was suggested by Anderson (1968) and to Charcot-Marie-Tooth disease (CMT1B; 118200) by Heimler et al. (1978), both on chromosome 1. Bale et al. (1985) provided a suggestion of linkage to amylase-2 (AMY2A; 104650) at 1p21. McConville et al. (1987) investigated linkage of BCNS with the NRAS oncogene locus (164790) on 1p13. However, Farndon and Simmons (1987) found negative lod scores with 5 markers on chromosome 1, suggesting that BCNS may not be on that chromosome.

In 1 of 5 affected related individuals, Fletcher and Morton (1988) found a constitutional chromosomal rearrangement involving chromosomes 5 and 15. The site involved on chromosome 5 was in the same approximate region on the long arm as that involved in adenomatous polyposis coli (APC; 611731). Fletcher and Morton (1988) noted similarities between BCNS and Gardner syndrome and proposed that they may be genetically related.