Background: CHARGE syndrome is a non-random clustering of congenital anomalies including coloboma, heart defects, choanal atresia, retarded growth and development, genital hypoplasia, ear anomalies, and deafness. A consistent feature in CHARGE syndrome is semicircular canal hypoplasia resulting in vestibular areflexia. Other commonly associated congenital anomalies are facial nerve palsy, cleft lip/palate, and tracheo-oesophageal fistula. Specific behavioural problems, including autistic-like behaviour, have been described. The CHD7 gene on chromosome 8q12.1 was recently discovered as a major gene involved in the aetiology of this syndrome. Methods: The coding regions of CHD7 were screened for mutations in 107 index patients with clinical features suggestive of CHARGE syndrome. Clinical data of the mutation positive patients were sampled to study the phenotypic spectrum of mutations in the CHD7 gene. Results: Mutations were identified in 69 patients. Here we describe the clinical features of 47 of these patients, including two sib pairs. Most mutations were unique and were scattered throughout the gene. All patients but one fulfilled the current diagnostic criteria for CHARGE syndrome. No genotype-phenotype correlations were apparent in this cohort, which is best demonstrated by the differences in clinical presentation in sib pairs with identical mutations. Somatic mosaicism was detected in the unaffected mother of a sib pair, supporting the existence of germline mosaicism. Conclusions: CHD7 mutations account for the majority of the cases with CHARGE syndrome, with a broad clinical variability and without an obvious genotype-phenotype correlation. In one case evidence for germline mosaicism was provided.

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Human congenital cataract and ocular anterior segment dysgenesis both demonstrate extensive genetic and phenotypic heterogeneity. We identified a family where ocular developmental abnormalities (cataract, anterior segment dysgenesis and microphthalmia) co-segregated with a translocation, t(5;16)(p15.3;q23.2), in both balanced and unbalanced forms. We hypothesized that this altered the expression of a gene of developmental significance in the human lens and ocular anterior segment. Cloning the 16q23.2 breakpoint demonstrated that it transected the genomic-control domain of MAF, a basic region leucine zipper (bZIP) transcription factor, first identified as an oncogene, which is expressed in vertebrate lens development and regulates the expression of the eye lens crystallins. The homozygous null mutant Maf mouse embryo demonstrates defective lens formation and microphthalmia. Through mutation screening of a panel of patients with hereditary congenital cataract we identified a mutation in MAF in a three-generation family with cataract, microcornea and iris coloboma. The mutation results in the substitution of an evolutionarily highly conserved arginine with a proline at residue 288 (R288P) in the basic region of the DNA-binding domain of MAF. Our findings further implicate MAF/Maf in mammalian lens development and highlight the role of the lens in anterior segment development. The 16q23.2 breakpoint transects the common fragile site, FRA16D, providing a molecular demonstration of a germline break in a common fragile site.

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The clinical features of the multiple pterygium syndrome are multiple congenital joint contractures, multiple skin webs, camptodactyly, vertebral anomalies, short stature, ptosis, and antimongoloid eye slant. We present 11 new cases to show the evolution of the full phenotype from birth and to confirm autosomal recessive inheritance. We emphasise morbidity secondary to respiratory impairment and that conductive deafness may be part of the syndrome. The designation multiple pterygium syndrome was used by Gorlin et al' in 1976 to describe an autosomal recessive disorder characterised by congenital arthrogryposis, skin webs (pterygia) across joints, and an unusual facies. A review by Escobar et a12 led to the alternative name Escobar syndrome, quoted by Smith.3 Hall et aP4 summarised findings in 42 reported cases adding seven new patients. Differentiation from other causes of congenital arthrogryposis may be difficult at birth since the typical facial appearance, pattern of finger contractures, and obvious webs usually develop over the first few years of life. We report 11 new cases of the syndrome to confirm the recessive mode of inheritance, to improve the diagnostic criteria, and to emphasise the uncertain prognosis. We suggest that conductive deafness may be part of the syndrome. Cases Case histories are presented in the following section. The clinical features are summarised in table 1 and the radiological abnormalities are presented in table 2 and the appendix. Selected radiographs are shown in fig 1. Case reports PATIENT 1 (MALE, 111.8, FIG 2) Patient 1 was born at term by normal delivery to a 38