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Decreased HLA heterogeneity in parents of children with Down syndrome

V D Mottironi, E B Hook, A M Willey

    American Journal of Human Genetics
    |November 1, 1983
    PubMed

    Insights

    Parents of children with Down syndrome (DS) showed a higher rate of shared Human Leukocyte Antigen (HLA)-A and B antigens. This suggests a potential link between parental HLA sharing and the occurrence or survival of trisomy 21.

    Area of Science:

    • Immunogenetics
    • Human Genetics
    • Reproductive Biology

    Background:

    • Human Leukocyte Antigen (HLA) genes play a crucial role in immune response and are highly polymorphic.
    • Down syndrome (DS), or trisomy 21, is a genetic disorder associated with specific chromosomal abnormalities.
    • Parental factors influencing the occurrence and survival of trisomy 21 pregnancies are of significant interest.

    Purpose of the Study:

    • To investigate the association between parental Human Leukocyte Antigen (HLA)-A and B antigen sharing and the occurrence of Down syndrome (DS) in their offspring.
    • To explore potential immunogenetic mechanisms contributing to trisomy 21.
    • To determine if shared HLA antigens influence the prenatal survival of fetuses with DS.

    Main Methods:

    • A standard microlymphocytotoxicity test was employed to determine HLA-A and B antigens.
    • The study included 37 couples with children diagnosed with trisomy 21 Down syndrome and 76 control couples with healthy children.
    • Statistical comparison of HLA antigen and haplotype sharing between the case and control groups was performed.

    Main Results:

    • No association was found between a specific HLA antigen or haplotype and parents of children with DS.
    • A significantly higher proportion of couples with DS offspring (43.24%) shared two or more HLA-A and/or B antigens compared to control couples (7.88%).
    • Among couples with shared HLA antigens, those with DS offspring were more likely to share a common haplotype (8/16) than control couples (2/76).

    Conclusions:

    • Parental sharing of HLA-A and B antigens is significantly more frequent in couples with Down syndrome offspring.
    • This increased antigen sharing may be linked to the higher incidence of trisomy 21 zygotes.
    • Parental HLA antigen sharing could also play a role in the prenatal survival of affected embryos and fetuses.

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