News | Negative Effect of High Genetic Homozygosity on Fertility Confirmed
University of California, Davis research found that increased genetic homozygosity—the presence of two identical alleles in the genome—negatively affects fertility in human populations. The study provided the first direct evidence that long-term homozygosity reduces reproductive capacity and was published in Proceedings of the National Academy of Sciences on October 17, 2023.
Effects on Fertility
The team analyzed genetic data from the Himba people of Namibia, who have relatively high inbreeding levels because of long-term marriage within a small population. Numerous long runs of homozygosity indicated that parents often shared ancestors.
Although Himba marriage practices allow men and women to have multiple partners, creating many paternal or maternal half-siblings, researchers found that this social structure delayed the genetic effects of inbreeding for several generations.
Reduced Fertility
The Himba value large families, with births commonly spaced one to three years apart. Women with greater genomic homozygosity had fewer children. Women whose parents were more closely related had significantly fewer children than women whose parents were more distantly related.
These genetic effects may accumulate across generations and eventually affect population fertility.
Future Research
The study provides important evidence about long-term effects of homozygosity on human reproductive health and suggests that prolonged inbreeding may affect the fertility of future generations in specific populations. Future work may examine ways to reduce population-health effects and develop related interventions.
News | Negative Effect of High Genetic Homozygosity on Fertility Confirmed
News | Negative Effect of High Genetic Homozygosity on Fertility Confirmed
University of California, Davis research found that increased genetic homozygosity—the presence of two identical alleles in the genome—negatively affects fertility in human populations. The study provided the first direct evidence that long-term homozygosity reduces reproductive capacity and was published in Proceedings of the National Academy of Sciences on October 17, 2023.
Effects on Fertility
The team analyzed genetic data from the Himba people of Namibia, who have relatively high inbreeding levels because of long-term marriage within a small population. Numerous long runs of homozygosity indicated that parents often shared ancestors.
Although Himba marriage practices allow men and women to have multiple partners, creating many paternal or maternal half-siblings, researchers found that this social structure delayed the genetic effects of inbreeding for several generations.
Reduced Fertility
The Himba value large families, with births commonly spaced one to three years apart. Women with greater genomic homozygosity had fewer children. Women whose parents were more closely related had significantly fewer children than women whose parents were more distantly related.
These genetic effects may accumulate across generations and eventually affect population fertility.
Future Research
The study provides important evidence about long-term effects of homozygosity on human reproductive health and suggests that prolonged inbreeding may affect the fertility of future generations in specific populations. Future work may examine ways to reduce population-health effects and develop related interventions.
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