McKusick–Kaufman syndrome is a genetic condition associated with MKKS. The condition is named for Dr. Robert L. Kaufman and

Victor McKusick Victor Almon McKusick (October 21, 1921 – July 22, 2008) was an American internist and medical geneticist, and Professor of Medicine at the Johns Hopkins Hospital, Baltimore. He was a proponent of the mapping of the human genome due to its us ...

. It is sometimes known by the abbreviation MKS. In infancy it can be difficult to distinguish between MKS and the related

Bardet–Biedl syndrome Bardet–Biedl syndrome (BBS) is a ciliopathic human genetic disorder that produces many effects and affects many body systems. It is characterized by rod/cone dystrophy, polydactyly, central obesity, hypogonadism, and kidney dysfunction in som ...

, as the more severe symptoms of the latter condition rarely materialise before adulthood. McKusick-Kaufman syndrome affects 1 in 10,000 people in the Old Order Amish population. Research has not identified cases outside of this population.

Presentation

Clinically, McKusick–Kaufman syndrome is characterized by a combination of three features: postaxial

polydactyly Polydactyly or polydactylism (), also known as hyperdactyly, is an anomaly in humans and animals resulting in supernumerary fingers and/or toes. Polydactyly is the opposite of oligodactyly (fewer fingers or toes). Signs and symptoms In humans ...

, heart defects, and genital abnormalities: * Vaginal atresia with

hydrometrocolpos A vaginal disease is a pathological condition that affects part or all of the vagina. Types Sexually transmitted infections Sexually transmitted disease that affect the vagina include: *Herpes genitalis. The herpes simplex virus (HSV) can infect ...

* Double vagina and/or uterus. *

Hypospadias Hypospadias is a common variation in fetal development of the penis in which the urethra does not open from its usual location in the head of the penis. It is the second-most common birth abnormality of the male reproductive system, affecting abou ...

chordee Chordee is a condition in which the head of the penis curves downward or upward, at the junction of the head and shaft of the penis. The curvature is usually most obvious during erection, but resistance to straightening is often apparent in the fl ...

(a downward-curving penis), and undescended testes (

cryptorchidism Cryptorchidism, also known as undescended testis, is the failure of one or both testes to descend into the scrotum. The word is from Greek () 'hidden' and () 'testicle'. It is the most common birth defect of the male genital tract. About 3% of ...

). * ureter stenosis or ureteric atresia

Genetics

MKS is inherited in an autosomal recessive dominance pattern. Both parents of the affected must be heterozygous carriers of the pathogenic variant. Heterozygous carriers for MKS show no symptoms of the disorder, nor can they develop the disorder. Each child of these carriers has a 1/4 chance of being affected by MKS, a 1/2 chance of being carriers themselves, and a 1/4 chance of being unaffected and a non carrier.

Diagnosis

Clinical findings support the diagnosis of MKS, including identification of biallelic pathogenetic variants. Diagnosis additionally requires ruling out Bardet-Biedl Syndrome.

Treatment

Treatments are available for accompanying symptoms of MKS, including addressing polydactyly and congenital heart defects.

References

External links