Velo-cardio-facial syndrome

DiGeorge syndrome, also known as 22q11.2 deletion syndrome, is a syndrome caused by the deletion of a small segment of chromosome 22. While the symptoms can vary, they often include congenital heart problems, specific facial features, frequent infections, developmental delay, learning problems and cleft palate. Associated conditions include kidney problems, hearing loss and autoimmune disorders such as rheumatoid arthritis or Graves disease.peripheral: Purine nucleoside phosphorylase deficiency DiGeorge syndrome, also known as 22q11.2 deletion syndrome, is a syndrome caused by the deletion of a small segment of chromosome 22. While the symptoms can vary, they often include congenital heart problems, specific facial features, frequent infections, developmental delay, learning problems and cleft palate. Associated conditions include kidney problems, hearing loss and autoimmune disorders such as rheumatoid arthritis or Graves disease. DiGeorge syndrome is typically due to the deletion of 30 to 40 genes in the middle of chromosome 22 at a location known as 22q11.2. About 90% of cases occur due to a new mutation during early development, while 10% are inherited from a person's parents. It is autosomal dominant, meaning that only one affected chromosome is needed for the condition to occur. Diagnosis is suspected based on the symptoms and confirmed by genetic testing. Although there is no cure, treatment can improve symptoms. This often includes a multidisciplinary approach with efforts to improve the function of the potentially many organ systems involved. Long-term outcomes depend on the symptoms present and the severity of the heart and immune system problems. With treatment, life expectancy may be normal. DiGeorge syndrome occurs in about 1 in 4,000 people. The syndrome was first described in 1968 by American physician Angelo DiGeorge. In late 1981, the underlying genetics were determined. The features of this syndrome vary widely, even among members of the same family, and affect many parts of the body. Characteristic signs and symptoms may include birth defects such as congenital heart disease, defects in the palate, most commonly related to neuromuscular problems with closure (velopharyngeal insufficiency), learning disabilities, mild differences in facial features, and recurrent infections. Infections are common in children due to problems with the immune system's T cell-mediated response that in some patients is due to an absent or hypoplastic thymus. DiGeorge syndrome may be first spotted when an affected newborn has heart defects or convulsions from hypocalcemia due to malfunctioning parathyroid glands and low levels of parathyroid hormone (parathormone). Affected individuals may also have other kinds of birth defects including kidney abnormalities and significant feeding difficulties as babies. Gastrointestinal issues are also verycommon in this patient population. Digestive motility issues may result in constipation. Disorders such as hypothyroidism and hypoparathyroidism or thrombocytopenia (low platelet levels), and psychiatric illnesses are common late-occurring features. Microdeletions in chromosomal region 22q11.2 are associated with a 20 to 30-fold increased risk of schizophrenia. Studies provide various rates of 22q11.2DS in schizophrenia, ranging from 0.5 to 2.0% and averaging about 1.0%, compared with the overall estimated 0.025% risk of the 22q11.2DS in the general population. Salient features can be summarized using the mnemonic CATCH-22 to describe 22q11.2DS, with the 22 signifying the chromosomal abnormality is found on the 22nd chromosome, as below: