Feingold Syndrome 1

A number sign (#) is used with this entry because Feingold syndrome-1 (FGLDS1) is caused by heterozygous mutation in the MYCN gene (164840) on chromosome 2p24.

Description

Feingold syndrome is an autosomal dominant disorder characterized by variable combinations of microcephaly, limb malformations, esophageal and duodenal atresias, and learning disability/mental retardation. Hand and foot abnormalities may include hypoplastic thumbs, clinodactyly of second and fifth fingers, syndactyly (characteristically between second and third and fourth and fifth toes), and shortened or absent middle phalanges. Cardiac and renal malformations, vertebral anomalies, and deafness have also been described in a minority of patients (summary by Teszas et al., 2006).

Genetic Heterogeneity of Feingold Syndrome

Feingold syndrome-2 (FGLDS2; 614326) is caused by hemizygous deletion of the MIR17HG gene (609415) on chromosome 13q31.3.

Clinical Features

Feingold (1975) reported a father, son, and grandmother with microcephaly, hand abnormalities, tracheoesophageal fistula, duodenal atresia, and normal intelligence. Feingold (1978) reported a mother and daughter with similar findings except for the absence of tracheoesophageal fistula and duodenal atresia.

Konig et al. (1990) described an affected mother and son with what they designated microcephaly, mesobrachyphalangy, and tracheoesophageal fistula (MMT) syndrome.

Brunner and Winter (1991) reported 2 families with an autosomal dominant syndrome of abnormalities of the hands and feet with short palpebral fissures, variable microcephaly with learning disability, and esophageal/duodenal atresia. The hand anomalies included flexion deformity of the middle finger and clinodactyly of the second and fifth fingers. Foot anomalies included bilateral syndactyly of toes 2-3 and 4-5. In the first family, the mother and 2 sons were affected, and 8 other family members had the same abnormalities of the hands and feet; 3 of them had had operations in the neonatal period for esophageal or duodenal atresia or both. There were no instances of male-to-male transmission. In the second family, a mother and son and daughter were affected. There was no consanguinity in either family. The phenotype of the syndrome was similar to that observed with 13q22-qter deletion, but chromosome analysis detected no structural abnormality in these familial cases.

Feingold et al. (1997) reported on 6 'new' families (12 patients) with this syndrome, updated the findings of the original families, and more clearly defined the syndrome. The most common findings were hand abnormalities, microcephaly, short and/or narrow palpebral fissures, broad nasal bridge, anteverted nostrils, ear abnormalities, and micrognathia. The features showed a significant amount of intrafamilial variability, especially as it related to the gastrointestinal findings. Although the first patients reported, who were very young, exhibited no developmental delay, they subsequently developed learning problems, and 87% of the 12 patients had mental retardation or learning difficulties. Typical hand findings, short second and fifth fingers, and clinodactyly and hypoplasia of the middle phalanx were pictured. Autosomal dominant inheritance was supported by the finding of male-to-male transmission in the family reported by Feingold (1975); in 8 of the 11 reported families, there was transmission through at least 2 generations.

Innis et al. (1997) reported what appeared to be the same condition in a family with 6 and probably 8 affected members in 3 generations, including instances of male-to-male transmission. They referred to the condition as autosomal dominant microcephaly with normal intelligence, short palpebral fissures, and digital anomalies. Affected individuals consistently had microcephaly (OFC less than 3rd centile) and short palpebral fissures; however, there was considerable variability and individual asymmetry in the defects of the limbs. Major limb anomalies were hypoplasia, slender thumbs with limited flexion at the distal interphalangeal joints of thumbs and some fingers, thin proximal first metacarpals, and short middle phalanges of the index and fifth fingers. None of the affected persons had polyhydramnios or duodenal atresia, but 1 individual had a history of tracheoesophageal fistula. Taken together with previous reports, the risk for tracheoesophageal fistula and/or duodenal atresia in this disorder was 8 in 29, or approximately 28%.

Frydman et al. (1997) described 4 families with what they considered to be the same disorder, which they called microcephaly-oculo-digito-esophageal-duodenal syndrome, or MODED. The phenotype is inherited as an autosomal dominant and includes microcephaly, type A brachydactyly, variable learning disabilities, short stature, duodenal atresia, patent ductus arteriosus (see 607411), hallux valgus, and a variety of digital anomalies. The authors reviewed previous reports, including their own observations. Penetrance of digital anomalies was almost complete. Microcephaly was present in 78% of known cases. Esophageal and duodenal atresias were found in 25% of known cases, but correction for ascertainment bias gave an estimate of 16.6%. Learning disabilities were seen in 31% of patients.

Courtens et al. (1997) reported a seventh family with Feingold syndrome. The propositus was a male infant with esophageal and duodenal atresia, brachymesophalangy of the fifth fingers, bilateral syndactyly of toes 4-5 (and 2-3), relative microcephaly, and facial anomalies. His mother also had microcephaly, similar facial appearance, short fifth fingers with single flexion crease, syndactyly of toes 4-5, and learning disabilities. A sister and brother of the mother and her mother had the same phenotype. A review of the 7 families with Feingold syndrome demonstrated that intestinal (esophageal/duodenal) atresia/obstruction occurs in approximately one-third of patients with Feingold syndrome.

Kawame et al. (1997) described 4 patients (2 boys and their mother and an unrelated girl) with microcephaly, normal intelligence, and digital abnormalities. The hand abnormalities were characterized by brachydactyly with radial clinodactyly of the fourth and fifth fingers, ulnar clinodactyly of the second fingers, and an increased space between the second and third fingers associated with an abnormal palmar crease that extended to the ulnar border. The foot abnormalities included short toes with syndactyly of the fourth and fifth toes. The mother had normal intelligence, and her sons and the unrelated girl had normal development. Kawame et al. (1997) noted similar findings in the patients reported by Feingold (1975) and Feingold et al. (1997), but suggested that the lack of gastrointestinal anomalies indicated that their 4 patients may have had a different autosomal dominant disorder.

Buttiker et al. (2000) described a father and daughter with characteristic features of Feingold syndrome including microcephaly, short palpebral fissures, brachydactyly with clinodactyly of fifth fingers, and bilateral syndactyly of second to third and fourth to fifth toes. The infant presented with long-gap esophageal atresia without fistula. Her father, who had short stature and learning disabilities, had congenital imperforate anus with a rectovesical fistula. The authors thought that this was first report of distal intestinal atresia in Feingold syndrome.

Shetty et al. (2000) described a 12-year-old girl with features of both the syndrome of microcephaly, mesobrachyphalangia, and tracheoesophageal fistula and Rett syndrome (312750). They suggested that this combination may constitute a new contiguous gene syndrome. However, the mapping of Rett syndrome to the X chromosome and the identification of the specific gene defect makes it unlikely that this was conventional Rett syndrome occurring as a contiguous gene syndrome with MMT syndrome, which maps to chromosome 2.

Piersall et al. (2000) reported an additional family, a father and 2 sibs, with ODED syndrome, which associates microcephaly, abnormalities of the hands and feet, shortened palpebral fissures, tracheoesophageal fistula, and duodenal atresia. Vertebral anomalies were noted in this family. The sacral spine demonstrated a sagittal cleft at the body of S4 and absence of S5. His father had blocked vertebra of C5, 6, and 7 and neural arch fusion on the left of the 6th and 7th vertebrae.

Shaw-Smith et al. (2005) and Shaw-Smith (2006) described a boy and his father with Feingold syndrome. They pictured short palpebral fissures and periorbital fullness, mild bilateral fifth finger clinodactyly, and in the father, bilateral clinodactyly of second and fifth fingers with brachymesophalangy of the second fingers. Shaw-Smith et al. (2005) observed short stature in the father and son and noted that of 18 cases of Feingold syndrome in the literature for which height was recorded, 4 had height at or below the 3rd centile, and 9 had height at or below the 10th centile; the authors suggested that short stature is likely to be a phenotypic feature of the syndrome.

Teszas et al. (2006) reported a 4-year-old boy with classic features of Feingold syndrome associated with a pathogenic mutation in the MYCN gene (164840.0004). The patient's mother and grandmother both carried the mutation and had microcephaly, fifth finger clinodactyly, partial syndactyly of the toes, and normal intelligence, consistent with microcephaly and digital abnormalities with normal intelligence syndrome as defined by Kawame et al. (1997). The mother also had chronic nephritis, renal insufficiency, and hypertension. Teszas et al. (2006) suggested that microcephaly and digital abnormalities with normal intelligence represents a milder form of Feingold syndrome.

Blaumeiser et al. (2008) reported monozygotic female twins with Feingold syndrome associated with a mutation in the MYCN gene (164840.0006). Both had the classic finger and toe malformations, hypertelorism, epicanthal folds, and developmental delay with occasional aggressive behavior. One sib had sensorineural deafness, and the other had duodenal atresia. Family history and genetic analysis showed that the mother and maternal grandfather also carried the mutation, but had only finger and toe anomalies. A maternal uncle of the twins also carried the mutation and had mental impairment, finger and toe anomalies, and structural renal problems. Blaumeiser et al. (2008) noted the wide phenotypic variability in this family.

Kocak et al. (2009) reported a Turkish boy with Feingold syndrome confirmed by genetic analysis. He had microcephaly, frontal balding, upslanting and short palpebral fissures, choanal atresia, micrognathia, and large ears. He had bilateral hypoplastic middle phalanges of the second and fifth fingers, syndactyly of the second and third toes, and overriding of the fourth and fifth toes. He presented at age 3.5 months with seizures and vomiting. Family history revealed an older sib with esophageal atresia who died, as well as 3 other miscarriages. The father, who also carried the mutation, had a small head and severe digital anomalies, with brachydactyly, brachymesophalangy of all fingers, and partial skin syndactyly of the second and third toes.

Inheritance

Feingold syndrome is inherited in an autosomal dominant manner (Feingold et al., 1997; van Bokhoven et al., 2005).

Mapping

Celli et al. (2000) studied 4 pedigrees with ODED syndrome, including a 3-generation Dutch family with 11 affected members. Linkage analysis was initially aimed at chromosomal regions harboring candidate genes, and 12 different genomic regions covering 15 candidate genes were excluded. A subsequent nondirective mapping approach revealed evidence for linkage to marker D2S390 (maximum lod of 4.51 at theta of 0.0). A submicroscopic deletion in the fourth family provided independent confirmation of this genetic localization and narrowed the critical region to 7.3 cM in the 2p24-p23 region. These results showed that haploinsufficiency for a gene or genes in 2p24-p23 is associated with ODED syndrome.

Tracheoesophageal fistula and esophageal atresia (TEF/EA) are common life-threatening conditions with multifactorial origins. Because these features occur in Feingold syndrome, this disorder may serve as a paradigm to identify genetic risk factors for TEF/EA. Van Bokhoven et al. (2005) carried out haplotype analysis in a previously unreported family with Feingold syndrome and confirmed linkage to the locus on chromosome 2 identified by Celli et al. (2003).

Molecular Genetics

In a previously unreported family with Feingold syndrome, van Bokhoven et al. (2005) found that affected members carried a microdeletion, which spanned a maximum interval of 1.2 Mb and encompassed the MYCN gene but no other known or predicted gene, making it an excellent candidate for Feingold syndrome. The MYCN gene had been shown to be activated by Sonic hedgehog (Shh; 600725) signaling and several lines of evidence suggest that the Shh pathway is disrupted in TEF/EA (Litingtung et al., 1998; Kenney et al., 2003; Oliver et al., 2003). In a cohort of 23 unrelated families with Feingold syndrome, van Bokhoven et al. (2005) sequenced the MYCN gene and identified 12 different heterozygous mutations in 15 families, including 3 different missense mutations at 2 adjacent arginine residues (164840.0001-164840.0003).

Marcelis et al. (2008) analyzed the MYCN gene in 93 patients from 50 families with a strong clinical suspicion of Feingold syndrome and identified 16 heterozygous mutations in 17 families with a total of 26 patients, including mutations in exon 2, which had not previously been reported (see, e.g., 164840.0007). The authors reviewed the clinical features of the 77 mutation-positive patients reported to date and compared them with the largest previous overview (Celli et al., 2003), and found that digital anomalies involving brachymesophalangy and toe syndactyly were the most consistent features, present in 100% and 97% of patients, respectively, whereas small head circumference was present in 89% of cases. Gastrointestinal atresia was the most important major congenital anomaly (55%), but renal and cardiac anomalies were also frequent (18% and 15%, respectively). Marcelis et al. (2008) suggested that the presence of brachymesophalangy and toe syndactyly in combination with microcephaly is enough to justify MYCN analysis.