Chondrodysplasia punctata 1 X - linked (X-linked chondrodysplasia punctata 1) - Gen RHEA
Chondrodysplasia punctata 1 X - linked it is a developmental disorder of cartilage and bone which occurs almost exclusively in males and is characterized by the presence of dotted near the ends of bones and cartilage when viewed X ray in most newborns affected, this stippling is observed in the bones of the ankles, toes and hands, but can appear in other bones. Generally, stippling disappears observed in early childhood. Other characteristic features of chondrodysplasia punctata 1 the X - linked include ends of the fingers of the unusually short stature feet and. This condition is also associated with distinctive facial features, particularly a nose flattened appearance in a crescent shape and a flat nasal bridge.
People with chondrodysplasia punctata 1 X - linked usually have normal intelligence and normal life expectancy; however, some affected individuals have had serious or fatal complications potentially including an abnormal thickening of airway cartilage, limiting breathing. In addition, abnormalities of the bones of the spine in the neck can cause pinching of the spinal cord, which can cause pain, numbness and weakness. Less common features include developmental delay, hearing loss, vision abnormalities and heart defects.
Chondrodysplasia punctata 1 The X - linked is due to genetic changes affecting the RHEA gene, located on the short arm of chromosome X (Xp22.3). This gene encodes the enzyme arylsulfatase E. Although the function of this enzyme is unknown, appears to be important for the normal development of the skeleton and is believed to participate in a chemical pathway involving vitamin K, which is normally involved in growth and maintaining bone density.
Between 60 and 75% of men with chondrodysplasia punctata characteristics of one X - linked, have a mutation in the gene MAPLE. These mutations reduce or eliminate the function of arylsulfatase E. Another 25% of affected males have a small deletion in the region of the X chromosome containing the gene ASS. In these individuals their cells arylsulfatase E condifican functional. Some people with chondrodysplasia punctata characteristics linked to X 1, have identified a mutation in the gene RHEA, so that other genetic and environmental factors, as yet unidentified, might be involved in the development of this condition.
This process is inherited as a recessive X - linked pattern in males, who have only one X chromosome, an altered copy of the gene in every cell ASS it is sufficient to express the disease. In females, having two X chromosomes, the mutation should occur in both copies of the gene for the disease is expressed. Because it is unlikely that women have two altered copies of this gene, males are affected by X - linked recessive disorders much more frequently than women. A feature of the X - linked inheritance is that fathers can not pass X - linked traits to their sons chromosome.
Tests in IVAMI: in IVAMI perform detection of mutations associated with condrodisplacia punctata 1 X-linked by complete PCR amplification of exons RHEA gene, and subsequent sequencing.
Samples recommended: EDTA blood collected for separation of blood leukocytes, or impregnated sample card with dried blood (IVAMI may mail the card to deposit the blood sample).
mail the card to deposit the blood sample).