Retinitis Pigmentosa 59



Test Description:

Retinitis pigmentosa (RP) is a degenerative eye disease resulting from retinal dystrophy, leading to loss of peripheral vision and blindness. RP is a heterogeneous disease, with many different causative genes that result in various subtypes. Many affected patients in the Ashkenazi Jewish population were found to have mutations in the gene DHDDS, which cause retinitis pigmentosa 59. In one study, 12% of RP patients with Ashkenazi Jewish ancestry had DHDDS mutations, whereas mutations in this gene accounted for less than 1% of RP in the general population. The p.K42E mutation accounts for over 97% of reported DHDDS mutations in the Ashkenazi Jewish population. Therefore, testing for this mutation is expected to identify over 95% of mutations in the Ashkenazi Jewish population, where the carrier frequency for this variant has been estimated at 1 in 117.

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. Zelinger L, Banin E, Obolensky A, Mizrahi-Meissonnier L, Beryozkin A, Bandah-Rozenfeld D, Frenkel S, Ben-Yosef T, Merin S, Schwartz SB, Cideciyan AV, Jacobson SG, Sharon D. A missense mutation in DHDDS, encoding dehydrodolichyl diphosphate synthase, is associated with autosomal-recessive retinitis pigmentosa in Ashkenazi Jews. Am J Hum Genet. 2011 Feb 1188(2):207-15.
2. Züchner S, Dallman J, Wen R, Beecham G, Naj A, Farooq A, Kohli MA, Whitehead PL, Hulme W, Konidari I, Edwards YJ, Cai G, Peter I, Seo D, Buxbaum JD, Haines JL, Blanton S, Young J, Alfonso E, Vance JM, Lam BL, Peri?ak-Vance MA. Whole-exome sequencing links a variant in DHDDS to retinitis pigmentosa. Am J Hum Genet. 2011 Feb 1188(2):201-6.
3. Venturini G, Koskiniemi-Kuendig H, Harper S, Berson EL, Rivolta C. Two specific mutations are prevalent causes of recessive retinitis pigmentosa in North American patients of Jewish ancestry. Genet Med. 2014 Sep 25. doi: 10.1038/gim.2014.132


Forms and Brochures




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:

81400


Forms and Brochures


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