Fraser Syndrome 1
Patient Information
Characteristics
Background and History
This is a rare and severe multisystem disorder affecting many parts of the body.
Clinical Correlations
The major characteristics of Fraser syndrome are fused eyelids (cryptophthalmos), fused digits, abnormalities of the reproductive organs and genitalia, and of the urinary system. The external genitalia may be ambiguous and the kidneys may be absent. The eyelids cannot be opened and the tear drainage system can be absent. The nasal openings and the ear canals are abnormally formed. Deafness may also be a feature.
Some infants are stillborn and many do not live beyond the neonatal period due to the extensive deformities.
Genetics
Inheritance
These infants are often born to related parents. This plus the horizontal family pattern with multiple infants with this condition are evidence of an autosomal recessive disorder. Those with this condition have two mutations in a specific gene while the clinically normal parents are carriers with only one copy of the mutations. Two such parents who each have a single mutation confer a 25% risk to each of their offspring to inherit this condition.
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
This disorder can be diagnosed by a multidisciplinary team of pediatricians, ophthalmologists, and urologists. The prognosis is poor with few surviving beyond the neonatal period. No treatment is available.
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