CASK-Related XLMR
The Ambry Test: CASK-Related XLMR includes gene sequence analysis of the CASK gene. Testing is also available for individual mutations in families in which a specific CASK mutation has previously been identified.
PrintThe Ambry Test: CASK-Related XLMR includes gene sequence analysis of the CASK gene. Testing is also available for individual mutations in families in which a specific CASK mutation has previously been identified.
Next-Gen Sequencing of CASK is also available as part of Ambry's XLMR Next-Gen SuperPanel™. It cannot be ordered separately.
General Information Mental retardation (MR) involves a complex collection of clinically and genetically diverse disorders. Diagnosis of MR is typically based on three main criteria: onset of symptoms before the age of 18, intellectual abilities significantly lower than average, and reduced adaptive skill. Individuals with MR tend to struggle in areas including communication, health, interpersonal/social skills, leisure, safety, self-guidance and care, school performance, and work.
X-linked mental retardation (XLMR) is associated with more than 200 conditions linked to >90 genes on the X chromosome. XLMR affects approximately 1/600-1/1000 males, as well as a significant number of females. Mutations in these genes have been shown to be an underlying cause of mental retardation, which may or may not be associated with other congenital anomalies, developmental delay, autism, dysmorphism, and numerous genetic syndromes. One of the XLMR-associated genes is CASK.
The calcium/calmodulin-dependent serine protein kinase gene (CASK) encodes a scaffolding protein that has been implicated in synaptic function and neural development. The CASK gene is located at Xp11.4 and contains 27 exons. Various types of mutations in the CASK gene have been reported in patients with syndromic and non-syndromic X-linked mental retardation. The clinical manifestations range from mild to severe mental retardation, occasionally accompanied by microcephaly, brain malformations, and facial dysmorphism (Hackett A et al. Eur J Hum Genet. 2010;18:544-552).
CASK gene testing should be considered for any individual with intellectual disability, mental retardation, developmental delay, learning disabilities of unknown cause, +/- microcephaly and nystagmus. Testing should also be considered for families with a history of CASK-related X-linked mental retardation or intellectual disability of unknown cause. Prenatal testing is available for families in which a CASK mutation has been identified.
The Ambry Test: CASK-Related XLMR is a gene sequence analysis performed by PCR-based double-stranded automated sequencing in the sense and antisense directions for exons 1-27 of the CASK gene, plus at least 20 bases into the 5’ and 3’ ends of all the introns. Specific mutation analysis for individual CASK mutations known to be in the family is also available.
This test detects an estimated 99% of all described CASK mutations. Mutations in the CASK gene account up to 1.5% of individuals affected with X-linked intellectual disability, microcephaly and nystagmus.1
Blood: Collect 3-5 cc from adult or 2 cc minimum from child into EDTA purple-top tube (first choice) or ACD yellow-top tube (second choice). Store at room temperature or refrigerate. Ship at room temperature.
Blood Spot: Call for availability.
Saliva: Collect 2 ml into Oragene™ DNA Self-Collection container. Store and ship at room temperature.
DNA: Send 20 μg in TE at 50-100 ng/μl. Store frozen and ship on ice or dry ice.
Prenatal: Prenatal testing is available. Please call an Ambry Genetic Counselor to discuss your case.
| Test Code | Technique | CPT Codes |
|---|---|---|
| 3180 | CASK Gene Sequence Analysis | 83891x1, 83894x26, 83898x27, 83904x52, 83909x52, 83912x1 |
| Technique | Days |
|---|---|
| CASK Gene Sequence Analysis | 21-35 |
1 Hackett A. et al. Euro J Hum Genet 2010;18:544-552.
2 Najm J. et al. Nature 2008;40(9):1065-1067.
3 Piluso G et al. Am J Hum Genet 2009;84:162-177.
4 Hsueh Y. et al. Nature 2000;41:298-302.