OMIM ID:
Baller-Gerold Syndrome
Alternate Names
Defective Genes
Clinical Characteristics
Ocular Features
The ocular features are a rather minor part of this syndrome and are found in less than a third of patients. These primarily involve lids and adnexae with telecanthus, downslanting lid fissures, and epicanthal folds. Some individuals have nystagmus while strabismus, blue sclerae, and ectropion have also been reported.
Systemic Features
The cardinal features of this syndrome are craniosynostosis and radial defects. However, a large number of variable defects such as imperforate or anteriorly placed anus, rectovaginal fistula, absent thumbs, polydactyly, and mental retardation may also be present. The radius may be completely absent or abnormally formed and occasionally the ulnar bone is involved as well. Some patients have a conductive hearing loss.
Genetics
Inheritance
This syndrome is caused by a mutation in the RECQL4 gene at 8q24.3 and seems to be an autosomal recessive disorder. Its syndromal status as a unique syndrome is in some doubt because of considerable phenotypic overlap with other entities such as Roberts (268300) and Saethre-Chotzen (101400) syndromes. The latter however is caused by a mutation in the TWIST1 gene and the former by mutations in the ESCO2 gene.
The same gene is mutated in Rothmund-Thomson syndrome (268400) suggesting allelism of the two disorders. The phenotype is vastly different in the two disorders however.
Pedigree
Autosomal recessive
In order for autosomal recessive disorders to be expressed, offspring generally must inherit two mutations, one from each carrier parent. Carriers with only one mutation, such as the parents, do not have clinical disease. Note that carrier parents can expect that 1 in 4 children (25%) will inherit both mutations and have the disorder, 2 in 4 children (50%) will be carriers like their parents, while 1 in 4 children (25%) inherit neither mutation.
In order for autosomal recessive disorders to be expressed, offspring generally must inherit two mutations, one from each carrier parent. Carriers with only one mutation, such as the parents, do not have clinical disease. Note that carrier parents can expect that 1 in 4 children (25%) will inherit both mutations and have the disorder, 2 in 4 children (50%) will be carriers like their parents, while 1 in 4 children (25%) inherit neither mutation.