Introduction: De novo mutations (DNMs) play a prominent role in sporadic disorders with reduced fitness such as infertility and intellectual disability. Advanced paternal age is known to increase disease risk in offspring by increasing the number of DNMs in their genome. Less is known about the effect of assisted reproduction techniques (ART) on the number of DNMs in offspring. With the on-going trend of delayed parenthood more children are now born both from older fathers and through ART. Materials and Methods: We investigated 49 trios (mother, father and child) and 2 quartets (mother, father and 2 siblings) divided into children born after spontaneous conception (n=18); born after in vitro fertilisation (IVF) (n=17) and born after intracytoplasmic sperm injection combined with testicular sperm extraction (ICSI-TESE) (n=18). Groups further divided by paternal age, young (<35) or old (>45 years of age at conception). Whole-genome sequencing was performed twice to independently detect and validate all DNMs in children. Results: A clear paternal age effect was observed, with 70 ... (Show More)

Introduction: De novo mutations (DNMs) play a prominent role in sporadic disorders with reduced fitness such as infertility and intellectual disability. Advanced paternal age is known to increase disease risk in offspring by increasing the number of DNMs in their genome. Less is known about the effect of assisted reproduction techniques (ART) on the number of DNMs in offspring. With the on-going trend of delayed parenthood more children are now born both from older fathers and through ART. Materials and Methods: We investigated 49 trios (mother, father and child) and 2 quartets (mother, father and 2 siblings) divided into children born after spontaneous conception (n=18); born after in vitro fertilisation (IVF) (n=17) and born after intracytoplasmic sperm injection combined with testicular sperm extraction (ICSI-TESE) (n=18). Groups further divided by paternal age, young (<35) or old (>45 years of age at conception). Whole-genome sequencing was performed twice to independently detect and validate all DNMs in children. Results: A clear paternal age effect was observed, with 70 DNMs detected on average in children born to young fathers and 94 DNMs in those born to older fathers (p = 0.001). No significant differences were observed between different methods of conception (p = 1) with paternal age affecting all methods equally. Conclusions: Paternal age, not method of conception, had a major effect on the observed number of DNMs in offspring. Given the role DNMs in disease risk, this negative result is good news for IVF and ICSI-TESE born children, if replicated in larger cohorts.

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