Abetalipoproteinemia



Test Description:

Abetalipoproteinemia is an autosomal recessive disease that causes the impaired absorption of dietary fats, cholesterol, and fat-soluble vitamins. Clinically, this impairment results in a failure to thrive, diarrhea, steatorrhea, and acanthocystosis. Severe vitamin deficiency may eventually cause ataxia and retinitis pigmentosa in affected adults. Abetalipoproteinemia is caused by mutations in the gene MTTP. While only about 100 patients have been reported in the literature, all reported patients with Ashkenazi Jewish ancestry have had one of two mutations, c.2212delT (p.S738Lfs*10) or c.2593G&gtT (p.G865*). Testing for these two mutations is expected to identify over 95% of carriers with Ashkenazi Jewish background, where the carrier frequency is estimated to be 1 in 186.

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. Sharp D, Blinderman L, Combs KA, Kienzle B, Ricci B, Wager-Smith K, Gil CM, Turck CW, Bouma ME, Rader DJ, et al. Cloning and gene defects in microsomal triglyceride transfer protein associated with abetalipoproteinaemia. Nature. 1993 Sep 2365(6441):65-9.
2. Narcisi TM1, Shoulders CC, Chester SA, Read J, Brett DJ, Harrison GB, Grantham TT, Fox MF, Povey S, de Bruin TW, et al. Mutations of the microsomal triglyceride-transfer-protein gene in abetalipoproteinemia. Am J Hum Genet. 1995 Dec57(6):1298-310.
3. Benayoun L, Granot E, Rizel L, Allon-Shalev S, Behar DM, Ben-Yosef T. Abetalipoproteinemia in Israel: evidence for a founder mutation in the Ashkenazi Jewish population and a contiguous gene deletion in an Arab patient. Mol Genet Metab. 2007 Apr90(4):453-7.



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