Ablepharon-Macrostomia Syndrome
Patient Information
Characteristics
Background and History
This is a recently described malformation syndrome whose characteristics have not been completely delineated. It has occurred in families but no causative gene mutation has been identified.
Clinical Correlations
Malformations occur in multiple structures throughout the body. The eyelids are often missing and the mouth opening is large. Scalp hair, eyelashes, and eyebrows are often missing. Vision may be affected when the cornea (windshield of the eye) dries out as a result of abnormal blinking. The bridge of the nose may be low, the nostrils are turned up, and the external ears may be tiny. Sometimes the fingers are short, partially fused, and lack full motion. The genitalia are often ambiguous and nipples can be absent. The skin is dry, coarse and often has extra folds. Some patients have hearing loss. Developmental milestones can be mildly delayed but intelligence is usually normal.
Genetics
Inheritance
Most reports suggest autosomal recessive inheritance but some authors suggest that other cases are inherited in an autosomal dominant patter. One patient with abnormalities in chromosome 18 has been reported.
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.
Diagnosis and Prognosis
Pediatricians in consultation with medical geneticists are likely to make the diagnosis. Ophthalmologists can confirm the characteristics of the eyelid malformations and suggest therapy for drying of the cornea. Plastic surgery can correct some of the facial and skin malformations. Lifespan is not shortened.
Web Resources
Printer Friendly Version: Ctrl/Cmd+P