Walker-Warburg Syndrome

Test ID:

703125

CPT code:

82360

Synonyms:

FUKUTIN
Jewish Heritage Test

Clinical Use:

Detection of the c.1167insA mutation on the FKTN gene, which accounts for approximately 99% of Walker-Warburg carriers in the Ashkenazi Jewish population.

Test Information:

Walker-Warburg syndrome (WWS, OMIM 236070) is an inherited, autosomal recessive disorder characterized by a triad of brain malformations, eye abnormalities, and congenital muscular dystrophy. The clinical findings include muscle weakness, hypotonia, feeding difficulties, blindness, seizures, and mal genital anomalies. Characteristic brain malformations include cobblestone lissencephaly, among other findings. Life expectancy is less than three years. The disease has an elevated prevalence in the Ashkenazi Jewish population, with a carrier rate of 1 in 150. When both parents are carriers of WWS, there is a 25% chance with each pregnancy of having a child with the disease. Prenatal diagnosis is available. Molecular genetic testing for WWS encompasses one founder mutation in the gene encoding fukutin (FKTN gene, 9q31). Testing for the c.1167insA mutation identifies approximately 99% of WWS carriers in the Ashkenazi Jewish population. The carrier frequency in the non-Ashkenazi Jewish population has not been determined. A negative result decreases the likelihood that the individual is a carrier but cannot completely eliminate the possibility. The presence of a rare mutation cannot be ruled out. DNA test results must be combined with clinical information for the most accurate interpretation.

Specimen Type:

Whole blood, amniotic fluid, chorionic villus sample (CVS) (Submission of maternal blood is required for fetal testing.), or buccal swab kit (Buccal swab collection kit contains instructions for use of a buccal swab.)