Toenail-patella syndrome is a rare genetic disorder that results in a person suffering from deformed or missing nails. In addition, there are numerous pathological changes in the skeletal system - lack or underdevelopment of the kneecap or deformation of the elbow joint. What are the causes and symptoms of toenail patella syndrome? What is the treatment?

Toenail-patella syndrome , also known as onychoosteodysplasia, onychoosteodystrophy, Turner-Kieser syndrome, Iliac-Horn syndrome or Fong's disease, is a rare genetic disorder whose essence is lack or inappropriate development nails and underdevelopment or incomplete or defective shape of the kneecap. In addition, there are other pathological changes in the skeletal system, urinary system and the organ of vision.

Toenail-patella syndrome: causes and inheritance

The cause of the disease is a mutation of the LMX1B gene in the 9q34.1 locus. It is a growth control gene that plays an important role in limb formation.

The prevalence of toenail-patella syndrome is estimated at 2.2 per 100,000 people.

The disease is inherited in an autosomal dominant fashion. The term "autosomal" means that the abovementioned the gene is inherited regardless of gender - both men and women can carry the gene with the mutation. The term "dominant" means that you only need to pass one copy of the disease-determining gene for the symptoms of the disease to appear.

Toenail-patella syndrome - symptoms

1. Lack (anonychia) or underdevelopment (dysplasia) of the nail plates:

  • are usually short and never reach the edge of the finger;
  • there are numerous discolorations;
  • their shape changes - depressions, grooves and furrows appear;
  • their shape changes (spoon nails, watch glass nails);
  • the nail plate may split, break, or even completely destroy;
  • nail diseases may appear, e.g. inflammation of the bed or nail shaft (paronychia);
  • the most severe changes usually involve thumb nails;

2. Absence or underdevelopment of the kneecap (the small, flattened bone in the knee joint) which leads to knee instability.In addition, there are other pathological changes in the skeletal system - bone growths in the hips, shoulder blades and elbows, deformation of the elbow joint and forearm bones, twisted feet and / or clubfoot, pathological scoliosis or lordosis.

3. Kidney dysfunctions - in 25-40 percent patients develop progressive nephropathy (damage to the kidneys leading to kidney failure).

4. Eye dysfunction - glaucoma, i.e. damage to the optic nerve, even leading to blindness.

5. There may also be excessive sweating or laxity of the skin.

Toenail-patella syndrome - diagnosis

Initial diagnosis can be made on the basis of the above-mentioned symptoms. The final diagnosis is made on the basis of the results of genetic testing.

Toenail-patella syndrome - treatment

The nail-patella syndrome is a genetic disease, therefore it is not possible to treat it causally - the patient will struggle with the disease for the rest of his life. Only symptomatic treatment is possible. For example, patients with nephropathy may require dialysis or kidney transplantation.

Category:

Genetic diseases