Central nervous system malformations in the Kraków region. II. Case control studies on the human leukocyte antigen genotype and haplotype frequencies.

A case control study of human leukocyte antigen haplotypes was performed on a sample of 44 index families of children with central nervous system (CNS) malformation and 36 families of healthy newborn infants. HLA typing for antigens determined by loci A, B, and C was done on parents and offspring. The HLA genotypes were inferred from segregation in families and the HLA gene and haplotype frequencies were obtained by direct gene counting. Case-control comparison did not uncover significant differences at any HLA allele. The haploytype pattern in the group of index cases did not show association with CNS malformations. The HLA phenotype compatibility among the probands' and controls' parents was within the same range except for locus C where parents of children with neural tube defects (NTD) less frequently shared common HLA-C antigens. The segregation of paternal haploytypes showed significant deviation in the families of NTD infants.