Syndrome, cartilage hair hypoplasia
A specific genetic form of short-limbed dwarfism with skeletal features that also include normal head, inability to fully extends the elbows, chest cage deformity, bow legs (genu varum), and the tibia shorter than the fibula. The fingers are usually loose-jointed and the fingernails foreshortened. Biopsy shows hypoplasia (underdevelopment) of cartilage to be the nature of the skeletal abnormality. The hair is unusually fine, sparse and light-colored. Microscopically, it has an abnormally small caliber. Many patients with cartilage hair hypoplasia have a major immunologic defect that is manifested, for example, as an unusual susceptibility to chickenpox. In addition to lymphopenia (lack of lymphocytes), some patients have anemia and neutropenia (lack of neutrophiliuc white blood cells). There is an increased malignancy risk, especially lymphoma and skin cancer. A condition called aganglionic megacolon (Hirschsprung disease) is also found in some patients. Cartilage hair hypoplasia was first recognized by McKusick and colleagues in 1965 as a distinct entity in the Old Order Amish, a religious isolate, but was later identified in other groups. In the original study of the Amish, 6 cases of fatal varicella (chickenpox) pneumonia were noted. Inheritance of the syndrome is autosomal recessive. The gene is on chromosome 9 in band 9p13. The child who receives the gene from both parents has the syndrome. Not everyone with the syndrome is dwarfed. Patients may be relatively tall; at least 1 Amish woman with the syndrome is 55 inches tall. There is a remarkable degree of variability in all features of the syndrome. The hair may be seemingly completely unaffected; some patients suffer no apparent immunologic or hematologic defect. Diagnosis of the syndrome in the first year or so of life may be difficult. Cartilage hair hypoplasia is sometimes written with a hyphen as cartilage-hair hypoplasia syndrome, is abbreviated CHH, and is also known as metaphyseal chondrodysplasia of the McKusick type. Perhaps the best known person with the syndrome was Billy Barty (1924-2000), the diminutive actor, who founded Little People of America, an important advocacy group for persons with all forms of dwarfism.

Medical dictionary. 2011.

Look at other dictionaries:

  • Cartilage–hair hypoplasia — Cartilage hair hypoplasia Classification and external resources OMIM 250250 Cartilage–hair hypoplasia (CHH), also known as McKusick type metaphyseal chondrodysplasia,[1]:578 is a rare form of short …   Wikipedia

  • Cartilage hair hypoplasia syndrome — A specific genetic form of short limbed dwarfism with skeletal features that also include normal head, inability to fully extends the elbows, chest cage deformity, bow legs (genu varum), and the tibia shorter than the fibula. The fingers are… …   Medical dictionary

  • Hypoplasia — Underdevelopment or incomplete development of a tissue or organ. For example, there can be hypoplasia (underdevelopment) of the enamel of the teeth. Hypoplasia is less drastic than aplasia where there is no development at all. * * * 1.… …   Medical dictionary

  • syndrome — The aggregate of symptoms and signs associated with any morbid process, and constituting together the picture of the disease. SEE ALSO: disease. [G. s., a running together, tumultuous concourse; (in med.) a concurrence of symptoms, fr. syn,… …   Medical dictionary

  • Shwachman–Bodian–Diamond syndrome — Shwachman–Diamond syndrome Classification and external resources OMIM 260400 DiseasesDB 11894 eMedicine …   Wikipedia

  • Shwachman-Diamond syndrome — Infobox Disease Name = PAGENAME Caption = DiseasesDB = 11894 ICD10 = ICD9 = ICDO = OMIM = 260400 MedlinePlus = eMedicineSubj = ped eMedicineTopic = 2060 MeshID = Shwachman Diamond syndrome (SDS) is a rare congenital disorder characterized by… …   Wikipedia

  • List of cutaneous conditions — This is an incomplete list, which may never be able to satisfy particular standards for completeness. You can help by expanding it with reliably sourced entries. See also: Cutaneous conditions, Category:Cutaneous conditions, and ICD 10… …   Wikipedia

  • Disease, Hirschsprung — A congenital abnormality (birth defect) of the bowel in which there is absence of the ganglia (nerves) in the wall of the bowel. Nerves are missing starting at the anus and extending a variable distance up the bowel. This results in megacolon… …   Medical dictionary

  • Hirschsprung disease — A congenital abnormality (birth defect) of the bowel in which there is absence of the ganglia (nerves) in the wall of the bowel. Nerves are missing starting at the anus and extending a variable distance up the bowel. This results in megacolon… …   Medical dictionary

  • List of diseases (C) — A list of diseases in the English wikipedia.C* C syndrome * C1 esterase deficiency (angioedema)CaCac Cal* Cacchi Ricci disease * CACH syndrome * Cafe au lait spots syndrome * Caffey disease * CAHMR syndrome * Calcinosis cutis (see also CREST… …   Wikipedia

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”