<\/p>\n
A large genome-wide association study identified sex-specific genetic differences in major depressive disorder, including a novel X-chromosome variant in males and higher heritability among females.<\/p>\n
The investigators analyzed genetic data from 130,471 female and 64,805 male patients with major depressive disorder (MDD) and more than 290,000 controls. Sixteen genome-wide significant variants were identified in females and eight in males. A male-specific variant, rs5971319, was located on the X chromosome near IL1RAPL1, a gene involved in neuronal development.<\/p>\n
Heritability estimates indicated a stronger genetic contribution to depression in females. Analyses of polygenicity showed a broader genetic basis for MDD in women. Genetic correlations were stronger between female MDD and body mass index (BMI), metabolic syndrome, attention-deficit\/hyperactivity disorder, and smoking than in males. Shared genetic regions across both sexes included NEGR1, while female-specific regions related to BMI involved genes such as DYNC1I2, HTT, and DENND1A.<\/p>\n
Most genetic variants influencing depression in males were found to overlap with those influencing females, suggesting a largely shared genetic foundation with sex-dependent effects.<\/p>\n
Investigators conducted sex-stratified genome-wide meta-analyses using international data sets. Linkage disequilibrium score regression estimated heritability, MiXeR modeled polygenicity and overlap, and gwas-pw identified shared or sex-specific causal regions.<\/p>\n
The study\u2019s limitations included an unequal sample size, which may have increased power to detect female-specific signals. Assumptions regarding lifetime prevalence and unscreened controls may also have influenced heritability estimates. Replication in a smaller independent cohort did not achieve statistical concordance, likely due to limited power.<\/p>\n
The investigators concluded that biological sex plays a key role in shaping depression\u2019s genetic architecture. Broader polygenicity and higher heritability in females may reflect the impact of female-specific variants and metabolic pathways, while the male X-linked finding highlights additional mechanisms that warrant study.<\/p>\n
Dr. Brittany L. Mitchell, PhD, of the Queensland Institute of Medical Research Berghofer Medical Research Institute in Brisbane, Australia, noted, \u201cThese insights into sex-specific genetic mechanisms not only deepen our understanding of the aetiology of MDD but may also inform the development of novel therapeutics that are tailored to sex-specific genetic risk profiles, ultimately contributing to more targeted and effective precision medicine strategies for MDD.\u201d<\/p>\n
The investigators reported no competing interests or conflicts of interest.<\/p>\n
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