A family with pericentric inversion of chromosome 12.

A heterozygous pericentric inversion of chromosome 12 (inv(12)) was prenatally diagnosed. The breakpoints were localized to p12.3 and q14, resulting in more than one-third of the total length of the chromosome being inverted. The inversions was transmitted from the father whose phenotype was completely normal. The newborn also showed normal phenotype and grew without any clinical problems. The parents had no history of infertility. Based on these facts, it is indicated that pericentric inv(12)(p12.3q14) does not affect phenotype.