Fragile X is one of the most common
causes of inherited mental retardation and neuropsychiatric
disease in humans. The syndrome is also
as FRAXA or the
The characteristic features of fragile X
in boys includes prominent ears, a long face,
delayed speech, large testes, hyperactivity,
tactile defensiveness, gross motor delays, and autistic-like
behaviors. Much less is known about girls with fragile
X syndrome. Only about half of all females who carry
the genetic mutation have symptoms.
Fragile X syndrome is due to a mutation
at an inherited site on the X chromosome, and
so is an X-linked disorder. Because the mutation
is dynamic, it can change in severity
from generation to generation, from person to person,
and even within a given person.
PCR analysis across the CGG region to determine allele size. This assay is sensitive for identifying premutation alleles. Southern analysis identifies large expansions of the CGG repeat region, and determines methylation status using Eco RI.
Methodology: PCR/Southern Blot
Purpose: Confirmation of Clinical Diagnosis
ICD-10 Code Q99.2
Test Requisition: Molecular Requisition
CPT Code: 81243 Cost:$401.00 Oklahoma Medicaid requires pre-authorization for this test.
Turn-around-time: 4 weeks
Specimen Requirements (Buccal Swabs cannot be accepted for this test)