Hand-Foot-Genital Syndrome

Clinical characteristics: Hand-foot-genital syndrome (HFGS) is characterized by limb malformations and urogenital defects. Mild-to-severe bilateral shortening of the thumbs and great toes, caused primarily by shortening of the distal phalanx and/or the first metacarpal or metatarsal, is the most common limb malformation and results in impaired dexterity or apposition of the thumbs. Urogenital malformations include abnormalities of the ureters and urethra and various degrees of incomplete müllerian fusion in females, and hypospadias of variable severity with or without chordee in males. Vesicoureteral reflux, recurrent urinary tract infections, and chronic pyelonephritis may occur; fertility is normal.

Diagnosis/testing: Diagnosis is based on physical examination including radiographs of the hands and feet and imaging studies of the kidneys, bladder, and female reproductive tract. Identification of a heterozygous HOXA13 pathogenic variant can establish the diagnosis if clinical and radiographic features are inconclusive. Approximately 50%-60% of pathogenic variants are polyalanine expansions.

Management: Treatment of manifestations: Hand or foot surgery is not usually necessary. Ureteric reimplantation and surgical correction of bladder outlet abnormalities are often necessary. Surgical removal of a longitudinal vaginal septum is rarely indicated. Surgery for removal of a uterine septum or reunification of a bicornuate uterus is exceptional in the absence of recurrent mid-trimester pregnancy loss. Hymenectomy may be necessary for tight constriction ring.

Prevention of secondary complications: Prophylactic antibiotics or surgery as needed to prevent urinary tract infections or other complications of ureteral reflux or ureteropelvic junction obstruction; gynecologic examination prior to menstruation for small hymenal opening; pre-pregnancy evaluation of the vaginal and uterine anatomy because of the increased risk for premature labor and fetal loss associated with structural abnormalities of the uterus.

Surveillance: Follow up with a urologist in the presence of vesicoureteral reflux and/or documented urinary tract infection.

Genetic counseling: Hand-foot-genital syndrome is inherited in an autosomal dominant manner. The proportion of cases caused by a de novo pathogenic variant is unknown because of the small number of individuals described. If a parent of the proband is affected, the recurrence risk to the sibs is 50%. If the proband has a known HOXA13 pathogenic variant that cannot be detected in the leukocyte DNA of either parent, the recurrence risk to sibs is slightly greater than that of the general population because of the possibility of parental germline mosaicism. Each child of an individual with HFGS has a 50% chance of inheriting the pathogenic variant. Prenatal testing for a pregnancy at increased risk and preimplantation genetic testing are possible if the pathogenic variant in the family is known.