Prenatal diagnosis of congenital hallux varus deformity associated with pericentric inversion of chromosome 9

Abstract

Congenital hallux varus is a rare deformity of the great toe characterized by adduction of the hallux and medial displacement of the first metatarsophalangeal joint. Prenatal diagnosis of congenital hallux varus is presented herein. A 32-year-old woman was referred to our unit due to significant deviation of the fetal right great toe at 22(+2) weeks of pregnancy. Ultrasound examination revealed a thick and short great toe, which was significantly angulated medially on the right side. Amniocentesis was performed and the result was reported as inv(9) (p11;q12). After delivery, the clinical examination confirmed the prenatal diagnosis. To our knowledge, this is the first reported prenatal diagnosis of an isolated congenital hallux varus. Congenital hallux varus can be diagnosed easily in the prenatal period by 2-D and 4-D ultrasonography. Prenatal karyotyping should be taken into consideration, especially in the presence of associated anomalies, such as polydactyly and clubfoot.

Congenital Hallux Varus: A Rare Prenatal Detection and Postnatal Management

“…Because inv ( 9) is commonly seen in the normal population, this was a coincidental finding as per this case report. 5 In our case, a variant of unknown significance was detected that was a heterozygous missense variant at exon 1 of the HOX A 13, which has an autosomal dominant inheritance for handfoot-genital syndrome. Hand-foot-genital syndrome and Guttmacher syndrome affect the distal limbs (minor manifestations) and genitourinary tract.…”

Pericentric inversion (Inv) 9 variant—reproductive risk factor or benign finding?

“…The pericentric inversion 9 variant is reportedly an exception to chromosome rearrangements that cause non-disjunction and by some authors has been noted to carry no increased reproductive risk [2, 4, 5], while other literature continues to suggest a clinical consequence associated with this inversion [6–12]. The pericentric inversion 9 variant involves the heterochromatic region of chromosome 9 and can occur with varying breakpoints.…”

“…Conflicting reports on the clinical significance of this inversion fuel the debate on the necessity of PGT-SR for couples with a carrier of the inversion. Some publications indicate the pericentric inversion 9 variant can be associated with unbalanced rearrangements [14], infertility [6–8], recurrent spontaneous abortions [9], and abnormal phenotype [10–12]. While others regard it as a benign population variant [2, 4, 5], supported by studies reporting no abnormalities in infants born with this inversion [15].…”