OMIM ID:
Cataracts, Congenital, Deafness, Short Stature, Developmental Delay
Alternate Names
Defective Genes
Clinical Characteristics
Ocular Features
The facial features superficially resemble those often seen in Down syndrome patients with slanting (up or down) lid fissures and epicanthal folds. The amount of ptosis is variable. Lens opacities are usually congenital in origin. Hypopigmentation of the macula has been noted in two individuals.
Systemic Features
The characteristic facies may be evident at birth and requires karyotyping to rule out the trisomy of Down syndrome. Brachycephaly and a flat face may be present. The mouth is often small and the nasal tip is shortened while the philtrum is long and smooth. Some degree of intellectual disability and neurosensory hearing loss soon become evident. There is postnatal growth delay and most individuals are short in stature. The ears are low-set and rotated posteriorly.
The skeletal anomalies are not fully delineated but one patient had bilateral radioulnar synostosis while hip chondrolysis requiring hip replacement has been seen in two adult individuals. Limited motion may be present in some joints, both large and small. Seizures have been reported in a few individuals. Nails may appear dystrophic and there are variable tooth anomalies present.
Genetics
Inheritance
The responsible heterozygous mutations are in the MAF gene (16q22-q23). Type 4 (CCA4) (610202) autosomal dominant cerulean cataracts with multiple morphologies may also result from mutations in this transcription factor gene.
Pedigree
Autosomal dominant
Autosomal dominant disorders require only one mutation for the disease to be expressed. Since an affected parent has two chromosomes, only one of which has the mutant gene, parents can expect that half (50%) of their children will receive that one and inherit the disease. It is common for individuals that inherit the mutation, however, to not have evidence of the disease (nonpenetrance).
Autosomal dominant inheritance leads to a vertical pattern of transmission