Maternally inherited 15q11-q13 duplications are generally found to cause more severe neurodevelopmental anomalies compared to paternally inherited duplications. However, this assessment is mainly inferred from the study of patient populations, causing an ascertainment bias. Here, we analyze the low coverage genome-wide cell-free DNA sequencing data obtained from pregnant women during non-invasive prenatal screening (NIPS). We detect 23 15q11-q13 duplications in 333,187 pregnant women (0.0069%), with an approximately equal distribution between maternal and paternal duplications. Maternally inherited duplications are always associated with a clinical phenotype (ranging from mild learning difficulties to intellectual impairment, epilepsy and psychiatric disorders), while paternal duplications are associated with milder phenotypes (from normal to learning difficulties and dyslexia). This data corroborates the difference in impact between paternally and maternally inherited 15q11-q13 duplications, contributing to the improvement of genetic counselling. We recommend reporting 15q11-q13 duplications identified during genome-wide NIPS with appropriate genetic counselling for these pregnant women in the interest of both mothers and future children.

Rapid advances in genetic testing techniques increase the possibility of finding a genetic diagnosis. In the case of couples who underwent a termination of pregnancy (TOP) due to foetal congenital malformations, these techniques might reveal the cause and meet the parent's need to know. The aim of this qualitative study is to explore the experiences of couples with being recontacted after TOP for congenital malformations, as well as the reasons for participating. A retrospective cohort of 31 couples was recontacted for additional genetic testing by sending a standardized letter followed by a telephone call. Fourteen couples (45%) agreed to participate. Data were collected through semi-structured interviews at the genetics department of the hospital (UZ Brussel). Interviews were audiotaped, transcribed and analysed using thematic analysis. We found that, despite the years that passed since the TOP, participants were still interested to perform novel genetic testing. They appreciated that the initiative for recontacting came from the medical team and described it as a sensitive approach. Both intrinsic (searching for answers for themselves and their children) and extrinsic motivators (contributing to science and helping other parents) were identified as important drivers of participation. These results show that, even after several years, many couples are still interested and motivated to be recontacted for further genetic testing. The results of this study can offer guidance in current debate on recontacting patients in the field of genetics.