OCULOCUTANEOUS ALBINISM TYPE 1 (OCA1)

Oculocutaneous Albinism (OCA) is a group of genetically heterogeneous hypopigmentation disorders including OCA1, OCA2, OCA3, and OCA4. All are inherited in an autosomal recessive manner. OCA1 has a prevalence of approximately 1/40,000 and is caused by mutations in the Tyrosinase (TYR) gene. Sequence analysis of the entire TYR gene is available on a clinical basis at the Medical Genetics Laboratories at Baylor College of Medicine.

Reasons For Referral:

• Confirmation of clinical diagnosis.
• Carrier testing of known familial mutations.
• Prenatal Diagnosis (known familial mutations).

Testing Methodology:

PCR amplification of all the five coding exons contained in the TYR gene coding region will be performed on patient genomic DNA. Direct sequencing of amplification products is performed in both the forward and reverse directions using automated fluorescence dideoxy sequencing methods.

Specimen Requirements:

Blood: EDTA (purple-top) tubes: Adults: 14 cc; Child: 6 cc; Infant: 2-3 cc
Requisition form must accompany the specimen. To receive forms, additional information or specimen collection kits, please contact the laboratory. Please call our laboratory for specific requirements for prenatal testing.

Turnaround Time:

Index: 4 weeks
Known Familial Mutation: 3 weeks

CPT Codes and Prices:

Index: 83912, 83894, 83891, 83898x10, 83904x20, 83909x20
Known Familial Mutation: 83912, 83894, 83891, 83898, 83904x2, 83909x2

Shipping Information

Forms:

 >> Gene Sequencing Requisition
 >> Prenatal Requisition

References:

1. Tomita, Y. et al (1989). Human oculocutaneous albinism caused by single base insertion in the tyrosinase gene. Biochem. Biophys. Res. Commun. 164: 990-996.

Test Codes:

Index: 6825
Known Familial Mutation: 6826
Prenatal (Known Familial Mutation Only): 6827

Medical Genetics Laboratories
Baylor College of Medicine · Houston, TX 77030
Phone: 1-800-411-GENE · Fax: 713-798-2787
E-mail: