Summary
Fraser syndrome is a rare clinical entity including as main characteristics cryptophthalmos and syndactyly. In total, about 150 affected patients have been described in the literature. Cryptophthalmos is present in 93% of cases and is marked by an absence of palpebral fissures with severe microphthalmia or anophthalmia, and absent or malformed lacrymal ducts. Syndactyly is present in 54% of cases. Urinary anomalies (absent or multicystic kidneys) and several other malformations were described in this syndrome: middle and outer ear malformations; high-arched palate; cleavage along the midplane of nares and tongue; hypertelorism; laryngeal stenosis; wide separation of symphysis pubis; displacement of umbilicus and nipples; mesenterium commune; fusion of labia and enlargement of clitoris, bicornuate uterus, and malformed Fallopian tubes in girls, and undescended testes and small penis with hypospadias in boys. Most patients have no intellectual deficit, but may display a set of severe handicaps. About 15% of cases were born to consanguineous parents, the transmission of the syndrome being autosomal recessive. The causative gene for Fraser syndrome (FRAS1) has recently been localized to 4q21. At least five mutations were identified in the FRAS1 gene, which encodes a putative extracellular matrix protein. Ultrasonographic diagnosis of the Fraser syndrome is feasible at 18 weeks gestation. It can be made if two of the following signs are present: microphthalmia, syndactyly, enlarged echogenic lungs, and oligohydramnios. Twenty-five per cent of affected infants are stillborn, while 20 % die before the age of 1 year from renal or laryngeal anomalies. If these anomalies are not present, the life expectancy is almost normal. *Author: Orphanet (March 2006)*.