LONG CHAIN 3-HYDROXYACYL-CoA DEHYDROGENASE DEFICIENCY (LCHAD)
MITOCHONDRIAL DNA ANALYSIS

Description:

Long chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) catalyzes the third step in the mitochondrial beta-oxidation spiral. LCHAD deficiency is usually evident in the neonatal period or in early childhood after a period of fasting or viral illness. Clinical manifestations include (1) Reye-like syndrome with hypoglycemia, fatty liver, and coma; (2) sudden unexplained death; (3) dilated or hypertrophic cardiomyopathy; or (4) skeletal myopathy. Isolated LCHAD deficiency in newborns may be associated with severe maternal illness occurring during pregnancies with affected fetuses. These maternal illnesses include the acute fatty liver of pregnancy (AFLP) syndrome; hypertension or hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome, and hyperemesis gravidarum. Target analysis for the two common mutations (1528G>C and 1132C>T) and sequence analysis of the entire coding region of the long-chain hydroxyacyl-CoA dehydrogenase (HADHA) gene are available on a clinical basis at the Medical Genetics Laboratories at Baylor College of Medicine.

Reasons for Referral:

Confirmation of a clinical diagnosis
Family history
Carrier testing
Mother with AFLP or HELLP syndrome

Testing Methodology:

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

Common Mutation Analysis: Our laboratory uses DNA amplification (PCR) and an automated mini-sequencing methodology to test for the 1528G>C and 1132C>T mutations in the LCHAD gene.

Specimen Requirements:

Blood: EDTA (purple-top) tubes: Adult: 14 cc; Child: 6 cc; Infant: 2-3 cc

Turnaround Time:

Full Sequencing: 4 weeks
Common Mutation Analysis: 2 weeks
Known Familial Mutation: 2 weeks

CPT Codes and Prices:

Full Sequencing: 83904x40, 83898x20, 83912, 83891, 83894x2
Common Mutation Analysis: 83904x4, 83898x2, 83912, 83891, 83894x2
Known familial mutation: 83904x4, 83898x2, 83912, 83891, 83894x2

Shipping Information

Forms:

>> Gene Sequencing Requisition

Test Codes:

Full Sequencing: 3120
Common Mutation Analysis:3122
Known Familial Mutation: 3121