Category genetic diseases

Definition Verruciform epidermodysplasia is a rare and inherited dermatological disease caused by a chronic human papillomavirus (HPV) infection. This pathology occurs already during childhood and, in most cases, is transmitted in an autosomal recessive manner (ie it is necessary to inherit two altered copies of the gene from both parents); there is no predilection for sex

Related articles: Focomelia Definition The phocomelia is a congenital malformation of the skeleton, characterized by the reduced or failure to develop the proximal segment of one or more limbs. Usually, the hands and feet have an almost normal conformation, but seem to be inserted respectively at the level of the shoulders and hips (similar to the limbs of seals)

Definition Hypertelorism is a congenital malformation characterized by an abnormal increase in the distance between two organs or parts of the body. Usually, it refers to the cranial deformation that distances the two eye sockets, caused by an excessive development of the sphenoid wings. The eyes are so far apart, separated by a nose whose root is enlarged

Related articles: Huntington's disease Definition Huntington's disease is an inherited disorder characterized by the progressive degeneration of specific areas of the brain. The cause is a mutation in the IT15 gene, located on chromosome 4 (4p16.3), which produces an abnormal repetition of the CAG sequence (cytosine-adenine-guanine) in the DNA

Definition Gaucher disease is a lysosomal storage disease, due to a deficiency of glucocerebrosidase and, in some cases, to the deficiency of the protein activator of saposine C. Glucocerebrosidase is an enzyme that normally hydrolyzes glucosylceramide (or glucocerebrosides) to glucose and ceramide. Enzyme deficits cause the formation of glucosylceramide and related components in the reticuloendothelial cells of the liver, spleen and bone marrow

Related articles: Imperfect osteogenesis Definition Imperfect osteogenesis includes a group of genetic diseases characterized by bone fragility and skeletal deformation of varying severity. Currently, based on radiographic features and molecular genetic analysis, we distinguish fifteen different types

Related articles: Tuberous sclerosis Definition Tuberous sclerosis is a neurocutaneous syndrome that affects several organs and causes the development of numerous tumors. The origin of this disorder is genetic and, mainly, depends on mutations occurring in two genes of tumor suppressors, TSC1 (chromosome 9) and TSC2 (chromosome 16)

Related articles: Turner syndrome Definition Turner syndrome is a syndrome associated with the partial or total absence of one of the two X chromosomes in the female sex. About 50% of women with Turner syndrome have only one X chromosome (karyotype 45, X); the remaining part presents instead an intermediate situation, in which one of the two chromosomes X is partially truncated or is absent only in some cells (mosaicism)

Related articles: Marfan syndrome Definition Marfan syndrome is a systemic disease characterized by an abnormality of connective tissue, which causes cardiovascular, musculoskeletal, ocular and pulmonary changes. This disease is generally transmitted in an autosomal dominant manner (ie the parent affected by the disease has a 50% chance of transmitting Marfan syndrome to each of their children), but sporadic forms have also been described

Related articles: Down syndrome Definition Down syndrome is a genetic disease characterized by the presence of an extra chromosome 21 compared to the normal pair (for this reason it is also known as trisomy 21). In some subjects with Down syndrome, on the other hand, the normal arrangement of 46 chromosomes is found, but a part of chromosome 21 is translocated to another chromosome (t (14; 21) is the most common defect)