Prenatal diagnosis of pericentric inversion in homologues of chromosome 9: a decision dilemma.

Pericentric inversion of one chromosome 9 [inv(9)] is considered a polymorphic variation and is one of the most common forms of autosomal inversion diagnosed prenatally in amniocytes. Yet its clinical significance remains uncertain. Most publications suggest that this finding is insignificant. However, some articles report on abnormal ultrasonic findings in association, such as hydramnios, anhydramnios, hydroureter, hydronephrosis, encephalocele, and prune belly syndrome. Other reports suggest that inv(9) might be one of the etiologies of psychiatric disorders. The homozygote state, on the other hand, is rarely encountered. We report two cases of pericentric inversion of the two homologues of chromosome 9. Two similar cases were previously reported. One affected fetus was had intrauterine growth restriction and the other had Walker-Warburg syndrome as opposed to the normal outcome of our patients. Finally, a workup of this finding is suggested.