Folate-related gene polymorphisms as risk factors for cleft lip and cleft palate

✍ Scribed by James L. Mills; Anne M. Molloy; Anne Parle-McDermott; James F. Troendle; Lawrence C. Brody; Mary R. Conley; Christopher Cox; Faith Pangilinan; David J. A. Orr; Michael Earley; Eamon McKiernan; Ena C. Lynn; Anne Doyle; John M. Scott; Peadar N. Kirke

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 104 KB
• Volume: 82
• Category: Article
• ISSN: 1542-0752
• DOI: 10.1002/bdra.20491

✦ Synopsis

Abstract

BACKGROUND:

Cleft lip with or without cleft palate (CLP) and cleft palate only (CPO) have an inherited component and, many studies suggest, a relationship with folate. Attempts to find folate‐related genes associated with clefts have, however, often been inconclusive. This study examined four SNPs related to folate metabolism (MTHFR 677 C→T, MTHFR 1298 A→C, MTHFD1 1958 G→A, and TC II 776 C→G) in a large Irish population to clarify their relationship with clefts.

METHODS:

Cases and their parents were recruited from major surgical centers performing cleft repairs in Ireland and a support organization. Data on risk factors, medical history, and DNA were collected. Controls were pregnant women from the greater Dublin area (n = 1,599).

RESULTS:

CLP cases numbered 536 and CPO cases 426 after exclusions. CPO mothers were significantly more likely than controls to be MTHFR 677 TT, OR 1.50 (95% CI: 1.05–2.16; p = .03). Log‐linear analysis showed a borderline association (p = .07). Isolated CPO case mothers were significantly more likely than controls to be homozygous for the MTHFD1 1958 G→A variant, OR 1.50 (95%CI: 1.08–2.09; p = .02). When multiple cases were added, both CPO cases and case mothers were significantly more likely to be AA (p = .02 and p = .007, respectively). The CLP case‐control and mother‐control analyses also showed significant effects, ORs 1.38 (95% CI: 1.05–1.82; p = .03) and 1.39 (95% CI: 1.04–1.85; p = .03), respectively.

CONCLUSIONS:

Associations were found for both CPO and CLP and MTHFD1 1958 G→A in cases and case mothers. MTHFR 677 C→T could be a maternal risk factor for clefts but the association was not strong. Because multiple comparisons were made, these findings require additional investigation. Given the known association between MTHFD1 1958 G→A and NTDs, these findings should be explored in more detail. Birth Defects Research (Part A) 2008. © 2008 Wiley‐Liss, Inc.