ObjectiveGenetic counseling and carrier screening are part of the gamete donation
process by healthy individuals. We aim to review the findings of genetic
counseling and carrier screening of a cohort of candidates at our public
gametes bank.MethodsThirty-four male and 64 female candidates had genetic counseling with a
medical geneticist before donation. Of these, one female candidate
voluntarily dropped-out. Thirty-four males and 63 females performed
karyotype and screening for the more common pathogenic variants forCFTR-related cystic fibrosis and spinal muscular
atrophy (SMN1) in the Portuguese population. In addition,
all females also performed Fragile X expansion screening
(FMR1). Thirty candidates with known or assumed African
ancestry performed hemoglobinopathies screening.ResultsSix candidates were definitely or temporarily withheld from the donation
process given their family or personal history that required further
investigation. Of 97 candidates tested, 16.5% presented anomalous laboratory
results (16/97): ten candidates were carriers for an autosomal recessive
disorder - cystic fibrosis (5/97), sickle cell anemia (3/30), and spinal
muscular atrophy (2/97). One female was anFMR1pre-mutation carrier (1/63). One female candidate presented with triple X
mosaicism: 47,XXX[2]/46,XX[50]. Two candidates presented with chromosomal
instability of unknown origin. In one candidate, a mosaic for the
Philadelphia chromosome was detected, revealing the diagnosis of chronic
myeloid leukemia.ConclusionsFrom a cohort of 97 candidates, 21.7% had a family/personal history or an
anomalous laboratory result that required additional genetic counseling,
stressing the importance of performing pre-donation genetic counseling in
this population.