Specimen

Blood

Collection Medium:

Minimum:

1-5 mL whole blood in EDTA

For Amniotic Fluid and CVS Specimens, please call laboratory.

Analytic Time:

8-10 weeks

Comments:

Please print, complete and submit the following forms to the lab, with 
the specimen and the A-1a Miscellaneous Request:

Informed Consent for DNA Testing

Sample Submission Form - Testing Services for Rare Mendelian 
Disorders from GeneDx DNA Diagnostic Experts.

Test
Limitations:

This group of related neurological syndromes with x-linked inheritance 
are allelic and are due to mutation in the L1CAM gene. Congenital 
hydrocephalus and resultant macrocephaly due to stenosis of the 
aqueduct of Sylvius may occur in isolation but is frequently associated 
with other features including hypoplastic or flexed, adducted thumbs. 
Patients are mentally retarded and have spastic paraplegia. MASA 
syndrome includes Mental retardation, Aphasia, Shuffling gait, and 
Adducted thumbs. In addition, CRASH syndrome in includes Corpus 
callosum agenesis/hypoplasia, Retardation, Adducted thumbs, Spastic 
paraplegia, and Hydrocephalus. There can be significant phenotypic 
variability within families, with some males severely affected and 
diagnosed prenatally while others may have no macrocephaly and long 
survival.

In the group of patients with a positive family history and more than 
one typical associated finding for L1CAM-associated disease, the 
detection rate of L1CAM mutations is greater than 90%.

Methodology:

Bi-directional Sequence Analysis

CPT Code:

83891(x20), 83898(x20), 83894(x20), 83904(x40), 83892(x4), 83912(x4)