Congenital Amegakaryocytic Thrombocytopenia



Test Description:

Congenital disorder of glycosylation type 1a (CDG-Ia, also known as PMM2-CDG) represents the most common form of N-linked oligosaccharide glycosylation disorders. CDG-Ia is inherited in an autosomal recessive manner, and is caused by mutations in the PMM2 gene. This disease may present in infancy, childhood or adolescents, and the clinical manifestations are highly variable. In infants, the disease may present as failure to thrive as a result of feeding problems later, the disease may manifest as encephalopathy, hypotonia, delayed language and motor development, intellectual disability, stroke-like episodes, and retinitis pigmentosa. The incidence of this disease is higher in people of Ashkenazi Jewish descent than in the general population their carrier frequency is estimated to be approximately 1 in 61. One mutation, p.R141H, comprises most of the mutant alleles in this community. Testing for the p.R141H mutation, as well as the p.P113L, p.F119L, and p.V231M mutations, is estimated to detect over 90% of mutations in the Ashkenazi Jewish population.

Full gene sequencing is available for reproductive partners of known mutation carriers. Prenatal diagnosis is also available. Prior to ordering prenatal testing, please contact our laboratory at 212-241-7518 to discuss.

References:
1. Kjaergaard, S., Schwartz, M. and Skovby, F. Congenital disorder of glycosylation type Ia (CDG-Ia): Phenotypic spectrum of the R141H/F119L genotype. Arch Dis Child. 85:236-239, 2001.



Specimen Requirements


Post-natal

Two 5-10 mL tubes of anticoagulated blood in EDTA (lavender top) or two 5-10 mL tubes of anticoagulated blood in ACD (yellow top).

Prenatal

Chorionic Villi: 5-10 mg in conical tube with sterile saline OR transport media
Amniotic Fluid: 10 ml in conical tube
Cultured Cells: Two confluent T-25 flasks

Additionally, please send:

5-10 ml maternal blood in EDTA (lavender top) required to perform MCC studies on all prenatal samples and in case maternal confirmation studies are necessary
5-10 ml paternal blood in EDTA (lavender top) in case paternal confirmation studies are necessary

Ordering Information


Shipping:

Ship at room temperature

Turnaround Time:

10 – 14 days

CPT Codes:

81401


Forms and Brochures


Carrier Screening Requisition and Consent [PDF]
Expanded Ashkenazi Jewish Carrier Screening Brochure [PDF]
Ashkenazi Jewish Carrier Screening Panel