Consanguinity in Primary Immunodeficiency Disorders; the Report from Iranian Primary Immunodeficiency Registry

TLDR

Primary immunodeficiency disorders are a heterogeneous group of genetic diseases with varied inheritance patterns. The study aimed to determine the frequency of consanguineous marriages among families of patients with primary immunodeficiency disorders. The authors reviewed records of 515 Iranian PiD patients over a 25‑year period. Consanguineous marriages were highly prevalent among Iranian PiD patients (65.6% overall, 38.6% national average), with rates ranging from 50% to 77.8% across specific immunodeficiency subtypes and being universal in patients with syndromic immunodeficiencies; the study recommends public education and premarital screening to reduce genetic disease risk.

Abstract

Problem Primary Immunodeficiency Disorders (PiD) are a heterogeneous group of genetic disorders, with different modes of inheritance. This study was accomplished in order to determine the frequency of consanguineous marriages in the families of patients with PiD. Method In this study, the records 515 Iranian PiD patients were reviewed during a 25‐year period. Results The mean proportion of consanguineous marriages was 65.6% among PiD patients, while the overall rate was 38.6% in the country. The rate of consanguinity was 77.8% in cellular immunodeficiencies, 75.8% in combined immunodeficiencies, 72.5% in defects of phagocytic function, 58.6% in other immunodefiiencies, 54.1% in predominantly antibody deficiencies, and 50% in complement deficiencies. Moreover all patients with immunodeficiency associated with other diseases had consanguineous parents. Such marriages were most common in the parents of patients with Chediak‐Higashi syndrome, severe combined immunodeficiencies, primary CD4 deficiency, ataxia‐telangiectasia, seletive IgG class deficiencies, chronic granulomatous disease, and Schwachman syndrome. Conclusions It is important to inform the general population about the dangers of consanguinity, which is very common in some areas such as Iran. Premarital examination to avoid genetic diseases could be suggested, especially in a community where the rate of consanguineous marriage is high.