OMIM ID:
CHOPS Syndrome
Alternate Names
Defective Genes
Clinical Characteristics
Ocular Features
There is usually some degree of proptosis and apparent hypertelorism. The eyebrows are bushy and the eyelashes are luxurious. One of three patients had cataracts and another had mild optic atrophy.
Systemic Features
The overall facial appearance may resemble Cornelia de Lange syndrome with hypertrichosis and a coarse, round facies. Head circumference is low normal. Septal defects and a patent ductus arteriosus are often present. Laryngeal and tracheal malacia predispose to recurrent pulmonary infections and chronic lung disease. Skeletal dysplasia includes brachydactyly and anomalous vertebral bodies resulting in short stature (3rd percentile). Genitourinary abnormalities include cryptorchidism, horseshoe kidney, and vesiculoureteral reflux. Delayed gastric emptying and reflux have been reported.
Genetics
Inheritance
Heterozygous mutations in the AFF4 gene (5q31.1) have been identified in 3 unrelated individuals with this condition. No familial cases have been identified. The gene is a core component of the super elongation complex that is critical to transcriptional elongation during embryogenesis.
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