7 research outputs found
Clinical applications of two-color telomeric fluorescence in situ hybridization for prenatal diagnosis: Identification of chromosomal translocation in five families with recurrent miscarriages or a child with multiple congenital anomalies
Searching for Genes for Cleft Lip and/or Palate Based on Breakpoint Analysis of a Balanced Translocation t(9;17)(q32;q12)
Evaluation Levels of Cytokines in Amniotic Fluid of Women with Intrauterine Infection in the Early Second Trimester
Sparseness, anti-sparseness and anything in between: The operating point of a neuron determines its computational repertoire
Neural tube defects (NTDs), including spina bifida and anencephaly, are common birth defects of the central nervous system. The complex multigenic causation of human NTDs, together with the large number of possible candidate genes, has hampered efforts to delineate their molecular basis. Function of folate one-carbon metabolism (FOCM) has been implicated as a key determinant of susceptibility to NTDs. The glycine cleavage system (GCS) is a multi-enzyme component of mitochondrial folate metabolism, and GCS-encoding genes therefore represent candidates for involvement in NTDs. To investigate this possibility, we sequenced the coding regions of the GCS genes: AMT, GCSH and GLDC in NTD patients and controls. Two unique non-synonymous changes were identified in the AMT gene that were absent from controls. We also identified a splice acceptor site mutation and five different non-synonymous variants in GLDC, which were found to significantly impair enzymatic activity and represent putative causative mutations. In order to functionally test the requirement for GCS activity in neural tube closure, we generated mice that lack GCS activity, through mutation of AMT. Homozygous Amt(ā/ā) mice developed NTDs at high frequency. Although these NTDs were not preventable by supplemental folic acid, there was a partial rescue by methionine. Overall, our findings suggest that loss-of-function mutations in GCS genes predispose to NTDs in mice and humans. These data highlight the importance of adequate function of mitochondrial folate metabolism in neural tube closure