The genetic architecture of pentanucleotide repeat variation and disease association.

Genetic variation in pentanucleotide tandem repeats shows extreme length and motif diversity at disease-associated loci in 47,952 genomes.

• Why it matters: Understanding PNTR variation is crucial because it underpins at least eleven neurological disorders, yet population-scale, sequence-resolved data have been lacking, hindering interpretation.
• What they did: The study genotyped nearly 48,000 PNTR loci across five ancestry groups using high-coverage long-read sequencing, validated with Oxford Nanopore data, and generated a detailed reference of length and sequence variation.
• The result: Disease-associated PNTR loci are identified as outliers with extreme repeat length and motif diversity, with repeat length and sequence composition often coupled, and variability converging on specific chromosomal backgrounds, exemplified by the SAMD12 locus.