By Emily Aldridge NS215G Mendelian and Human Genetics Nail Patella Syndrome By Emily Aldridge NS215G Mendelian and Human Genetics

Nail Patella Syndrome (NPS) Overview Also Known as Fong Disease and Turner-Kieser Syndrome. Hereditary disorder Known as an inherited disorder for over 100 years. Affects the nails, skeletal system, and kidneys. 1/50,000 people Affects males and females equally. Occurs in all ethnic groups Strongest risk for NPS is a family history.

The Cause of NPS Mutated gene LIM Homebox Transcription Factor 1-Beta (LMX1B). Located on the long arm of chromosome 9 Codes for a protein that is important in organizing embryonic limb development. Inherited in an autosomal dominant manner. Possession on only 1 copy of the defected gene is enough to cause disease. Child has 50/50 chance to inherit the disease-causing mutation.

NPS Symptoms Medical signs vary widely between patients. Some don’t display symptoms. Discovered to have NPS only when genetic studies trace their family history. Scientist doing studies to find out why some people display symptoms and others don’t.

Thumbnail affected by NPS Nails Found in 80 % of NPS Patients One or more fingers but rarely all. Affects mostly thumb and index finger nails. May be small and concave with pitting, ridges, splits, and/or discoloration. Lunula are sometimes triangular. Toenails are less often affected. Thumbnail affected by NPS

Knee Caps NPS Kneecap One or both may be missing or poorly developed. If present likely to dislocate. Knees have a square appearance. Beside the knee cap, other support structures such as bones, ligaments, and tendons maybe malformed. Since these stabilized the knee cap, can cause it to be painful or difficult to walk.

Hip Bones 80 % of patients have bony projections called posterior iliac horns. Internal/not obvious unless detected on x-ray. Not associated with any other disease.

Kidney Disease Incidence of Kidney Disease in NPS patients is approximately 30-50% More apparent later in life. Should have regular urinalysis to monitor changes in kidney function.

Feet and Ankles Many are born with a club foot deformities due to misplacement of tendons around the foot and ankle.

Detection Diagnosis is often made on visual medical clues such as the abnormalities of nails and kneecaps. Confirmed by x-rays of the affected bones. Prenatal Diagnosis (as of 2001)is not yet widely available. Genetic Testing is available as of early 2001 Only through research institutes that are working to further characterize this disorder. Can’t predict which signs will develop and the severity of the symptoms. Improved genetic tests are anticipated in the future.

Treatment Not usually necessary Kidney treated with dialysis or transplant. New kidney won’t be affected. If walking becomes too painful the patient will have to resort to a wheelchair. Orthopedic surgery may be necessary for congenital (a condition present at birth)clubfoot. Manipulation or surgery to correct hip dislocation. Should be screened for scoliosis.

Many people who have Nail Patella Syndrome go on to live a normal and healthy life.

Bibliography Club Foot Picture. CDC Public Health Image Library. Dunston, Jennifer A., Tyler Reimschisel, Yu-Qiang Ding, Elizabeth Sweeney, Randy L. Johnson, Zhou-Feng Chen, and Iain McIntosh. "A neurological phenotype in nail patella syndrome (NPS) patients illuminated by studies of murine Lmx1b expression." European Journal of Human Genetics 13 (2005): 330-35. Lohr, John T. "Nail-Patella Syndrome." HealthAtoZ. 14 Aug. 2006. 26 July 2008 <http://http://www.healthatoz.com/healthatoz/atoz/common/standard/transform.jsp?requ esturi requestURI=/healthatoz/Atoz/ency/nail-patella_syndrome.jsp Mansour, Joanne, ed. "What is NPS." Nail Patella Syndrome Worldwide. 26 July 2008 <http://www.nailpatella.org>. Nail Patella Syndrome. Journal of Medical Genetics. Wijten, Jan. Nail Patella Syndrome. 6 Dec. 2006.