Whole-genome sequencing of 1,171 elderly admixed individuals from Brazil

As whole-genome sequencing (WGS) becomes the gold standard tool for studying population genomics and medical applications, data on diverse non-European and admixed individuals are still scarce. Here, we present a high-coverage WGS dataset of 1,171 highly admixed elderly Brazilians from a census-based cohort, providing over 76 million variants, of which ~2 million are absent from large public databases. WGS enables identification of ~2,000 previously undescribed mobile element insertions without previous description, nearly 5 Mb of genomic segments absent from the human genome reference, and over 140 alleles from HLA genes absent from public resources. We reclassify and curate pathogenicity assertions for nearly four hundred variants in genes associated with dominantly-inherited Mendelian disorders and calculate the incidence for selected recessive disorders, demonstrating the clinical usefulness of the present study. Finally, we observe that whole-genome and HLA imputation could be significantly improved compared to available datasets since rare variation represents the largest proportion of input from WGS. These results demonstrate that even smaller sample sizes of underrepresented populations bring relevant data for genomic studies, especially when exploring analyses allowed only by WGS

Recurrent miscarriage in a balanced chromosomal translocation carrier

ABSTRACT This case report describes a 30-year-old female patient, carrier of a balanced chromosomal translocation. The patient has a past of three consecutives abortions, the first two losses during the tenth week of pregnancy and the third during the eighth week. This situation motivated the couple to seek the obstetrics & gynecologic professional at the Basic Health Care Unit, who referred them to the Genetic ambulatory care. Karyotype reveals the female patient carries a balanced chromosomal translocation, being 46,XX, t(1;16)(p36;q22), while her partner is normal 46,XY. Such chromosomal abnormality is largely linked with recurrent miscarriage in early pregnancy and the risk of birth of an abnormal child, therefore it is recommended genetic counseling and assisted reproduction if another pregnancy is desired