Bosma Arhinia Microphthalmia Syndrome
Patient Information
Characteristics
Background and History
This is an extremely rare condition with facial and other developmental abnormalities affecting both sexes.
Clinical Correlations
Infants are born without a nose often with missing facial bones and they may be unable to smell. The eyes can be small or appear to be missing (clinical anophthalmos) and there is usually a defect in the iris (coloboma). The face appears to be underdeveloped and the palate is often highly arched or cleft.
The penis is abnormally small and the testes are underdeveloped. Females often experience delayed puberty and have menstrual irregularities. There are usually abnormalities of the anal-urinary openings.
Intelligence is usually normal.
Genetics
Inheritance
This disorder results from a mutation (change) in a specific gene. It is an autosomal dominant condition which can be passed directly from parent to child. There is considerable variation in the severity of the clinical features such that mildly affected individuals whose reproductive systems are fully functional are able to have children whereas many others cannot.
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
Diagnosis and Prognosis
Newborns with the full clinical characteristics are likely to be diagnosed based on the facial and genital features. Pediatricians and geneticists trained in the evaluation of congenital malformations (dysmorphologists) are likely to collaborate on the diagnosis. It is important to determine the levels of sex hormones at an appropriate point and gene studies are useful to confirm the diagnosis.
Individual facial malformations may be surgically correctable. There is no treatment, though, for the small eyes and vision can be significantly impaired
No quantitative data on longevity are available.
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