Diseases

Homozygous hypobetalipoproteinemia

Inherited low blood betalipoprotein level. The type and severity of symptoms is determined by whether or not there are some betalipoproteins in the body.

Hooft disease

A rare disorder characterized by mental and physical retardation, red rash and low blood lipid level

Hoon Hall syndrome

A very rare syndrome characterized mainly by dislocated joints and various other skeletal abnormalities.

Horn Kolb syndrome

congenital malformation involving symmetrically absent hands and feet. Little lumps on the ends of the limbs may be all that remains of the fingers and toes.

Horner’s syndrome

Horner syndrome is a rare condition that affects the nerves to the eye and face.

Hornova Dlurosova syndrome

A rare disorder characterized by mental retardation and amyloid (abnormal protein) deposits in the eyelids and gums.

Horseshoe kidney

The horseshoe kidney is the most common type of renal fusion anomaly. It consists of two distinct functioning kidneys on each side of the midline, connected at the lower poles by an isthmus of functioning renal parenchyma or fibrous tissue that crosses the midline of the body.

Horton’s disease

A systemic autoimmune vasculitis occurring primarily in people over the age of 50. Pathologic features include a necrotizing panarteritis including granulomas and giant cells. There is a predilection for involvement of central nervous system blood vessels and the most frequent neurologic complication is an OPTIC NEUROPATHY, ISCHEMIC. Large blood vessels may become involved, including the aorta. Clinical manifestations may include myalgias, weight loss, headache, visual loss, necrosis of the skin or tongue, and chest discomfort. Superficial scalp arteries may become tender and enlarged. A related condition, juvenile temporal arteritis, tends to occur in the first or second decade of life.

Howard Young syndrome

A very rare syndrome characterized mainly by a small head, facial cleft and an extra big toe. More detailed information about the symptoms, causes, and treatments of Howard-Young syndrome is available

Hoyeraal-Hreidarsson syndrome

Hoyeraal-Hreidarsson syndrome (HHS) is a very rare multisystem X-linked recessive disorder characterized by excessively short telomeres and is considered a severe form of dyskeratosis congenita. Being an X-linked disorder, HHS primarily affects males. Patients with HHS typically present in early childhood with cerebellar hypoplasia, immunodeficiency, progressive bone marrow failure, and intrauterine growth retardation. The primary cause of death in HHS is bone marrow failure, but mortality from cancer and pulmonary fibrosis is also significant.

Human granulocytic ehrlichiosis

A rare infectious condition caused by infection with a type of bacteria called Ehrlichia (Anaplasma phagocytophilia) which attack granulocytes (a type of white blood cell). The infection is transmitted by the deer and American dog tick

Human monocytic ehrlichiosis

A rare infectious condition caused by infection with a type of bacteria called Ehrlichia (Ehrlichia chaffeensis) which attack monocytes(a type of white blood cell). The infection is transmitted by the Lone Star and American dog tick

Human T Cell Leukemia Virus 1

Human T-cell leukemia virus type 1 (HTLV-1) is an oncogenic retrovirus associated primarily with adult T-cell leukemia and neurological disease. HTLV-1 encodes the positive trans-regulatory proteins Tax and Rex, both of which are essential for viral replication

Human T-cell leukemia viruses type 2

Human T-cell leukemia virus (HTLV) type 1 and type 2 are related but distinct pathogenic complex retroviruses. HTLV-1 is associated with adult T-cell leukemia and a variety of immune-mediated disorders including the chronic neurological disease termed HTLV-1-associated myelopathy/tropical spastic paraparesis. In contrast, HTLV-2 displays distinct biological differences and is much less pathogenic, with only a few reported cases of leukemia and neurological disease associated with infection. In addition to the structural and enzymatic proteins, HTLV encodes regulatory (Tax and Rex) and accessory proteins.

Human T-lymphotropic virus type 3

Human T-lymphotropic virus type 3: A former name used for HIV which is an infectious viral disease. The infection usually has an initial symptom-free period which is followed by various stages of increasing severity.

Humeroradial synostosis

A rare genetic disorder characterized by fusion of the humerus (upper arm) and radial (lower arm) bones as well as other anomalies

Humerus trochlea aplasia of

A very rare syndrome characterized by arm abnormalities primarily involving the absence of a part of the upper arm called the trochlea. The trochlea is the end of the arm bone which allows arm movement through it's pulley-like structure.

Hunter Macpherson syndrome

A very rare disorder characterized by the association of mental retardation and abnormal bone hardening

Hunter Mcdonald syndrome

A rare syndrome characterized mainly be short stature, characteristic facial appearance and a predisposition for developing brain tumors.

Hunter Syndrome

Hunter syndrome or Mucopolysaccharidosis II (MPS II) is an inherited disorder of carbohydrate metabolism that occurs almost exclusively in males. It is characterized by distinctive facial features, a large head,  hydrocephalus, enlargement of the liver and spleen (hepatosplenomegaly), umbilical or inguinal hernia, and hearing loss. Individuals with this condition may additionally have joint deformities and heart abnormalities involving the valves. MPS II is caused by mutations in the IDS gene and is inherited in an X-linked manner.

There is a wide range in severity of symptoms present in individuals with MPS II. Previously, MPS II was classified as severe and attenuated based on severity. More recently, the terms slowly progressive and early progressive have been suggested. While both types affect many different parts of the body, people with the severe type also experience a decline in intellectual function and a more rapid disease progression. The life expectancy for people with the severe type is 10 to 20 years. Individuals with the less severe type typically live into adulthood and intelligence is not affected. Treatment is focused on managing the signs and symptoms present in each individual.

Hunter-McAlpine syndrome

A very rare dominantly inherited syndrome characterized mainly by premature fusion of skull bones, mental retardation, small mouth, short stature and finger and toe anomalies