© 2018, GENASSIST, Inc.            

By Keith S. Wexler, MBA, CFO, Business Development Director, GENASSIST, Inc.

Paul Wexler, M.D., F.A.C.O.G., Medical Director, GENASSIST, Inc.

Clinical Professor, Department of OB/GYN, University of Colorado Health Sciences Center

Clinical Professor, Division of Genetics/Dept. of Pediatrics, Univ. of Colorado/The Children’s Hospital

There are many disorders that have been linked to the X chromosome (e.g. hemophilia, some types of muscular dystrophy and male developmental delay.

The Y chromosome is quite small and contains relatively few genes which nonetheless are still very important. Several of the genes are linked to male infertility and spermatogenesis and have been identified on the long arm (q-arm) of the Y chromosome (Yq11.2-11.22) including USP9Y, CDY1, DAZ1, DAZ2, DDX3Y, HSFY1 and RBMY1A1.

The SHOX gene identified on the short arm of both the X chromosome (Xp22.33) and the Y chromosome (Yp11.3) has a role in bone growth and maturation.

Mutations in the SHOX gene have been implicated in shortening of the arms and legs including Langer Mesomelic Dysplasia, Leri-Weil Dyschondrosteosis and Turner Syndrome.

  • The SRY gene (Sex Determining Region on the Y chromosome) is also located on Yp11.3
  • The SOX9 gene on chromosome 17q24.3 is related to the SRY gene and plays a role in bone growth

Swyer Syndrome – a disorder reported in approximately 1:86,000 newborn females also called 46,XY Complete Gonadal Dysgenesis presents with female genitalia and a nonfunctional SRY gene. Mutations in the SRY gene n have been identified in up to 15% of these children who may also present with neuropathy and skeletal abnormalities, usually Campomelic Dysplasia.

Other disorders linked to the Y chromosome include:

  • Retinitis Pigmentosa linked to the RPY gene
  • Jacobs Syndrome (XYY)
  • Hypertrichosis Pinnae (excessive ear hair)