Diseases

Hereditary type 2 neuropathy

Hereditary sensory and autonomic neuropathy, type 2 (HSAN2) is an inherited disorder characterized by profound and universal sensory loss involving large and small fiber nerves, and marked hypotonia. The exact prevalence is unknown, but is estimated as very low (less than 50 cases reported). HSAN2 presents in infancy or early childhood and is non-progressive. There is no sex preference or particular ethnic preponderance, and to date there is no increased incidence of consanguinity.

Hereditary Xerocytosis

Hereditary stomatocytosis and hereditary xerocytosis are rare, genetically distinct, autosomal dominant diseases of red blood cell sodium and potassium permeability. Hereditary cryohydrocytosis is a subtype of hereditary stomatocytosis. All three present with hemolysis and anemia, which can vary from mild to severe. The key signs and symptoms are those of all hemolytic anemias: jaundice, pallor, fatigue, splenomegaly, gallbladder disease, and susceptibility to an aplastic crisis following infection with parvovirus B19. The diseases begin at birth, but especially in the case of hereditary xerocytosis and hereditary cryohydrocytosis, may be mild enough to go undiscovered for years.

Hermansky Pudlak syndrome 2

A rare disorder characterized by various degrees of albinism, bleeding due to a platelet defect, an accumulation of a waxy substance in cells (lysosomal ceroid storage) and immunodeficiency. HPS type 2 differs from type 1 in that it also involves immunodeficiency due to congenital neutropenia.

Hermansky-Pudlak syndrome

Hermansky-Pudlak syndrome (HPS) is a rare disorder characterized by various degrees of albinism, bleeding due to a platelet defect and accumulation of a waxy substance in cells (lysosomal ceroid storage).

Hermaphroditism

A very rare genetic disorder where a baby is born having both male and female internal sex organs

Hernandez Aguirre-Negrete syndrome

A very rare syndrome characterized mainly by mental retardation, epilepsy and a bulbous nose. The condition has been reported in only two families.

Herpes simiae (B virus)

A type of herpesvirus which occurs in monkeys but can be transmitted to humans through bites or through contact with infected monkey tissue as in a laboratory situation. The virus infects the brain (encephalitis) and the surrounding membrane (meningitis).

Herpes simplex encephalitis

A form of encephalitis caused by the herpes simplex virus and characterized by fever, headache and neurological symptoms.

Herpes zoster ophthalmicus

Varicella-zoster virus (VZV) causes 2 distinct syndromes. The primary infection (chickenpox) is a contagious and usually benign febrile illness. Following this infection, virus particles remain in the dorsal root or other sensory ganglion where they may lay dormant for years to decades. As a result of aging, immunosuppressive illness, new stress, or medical treatments, the virus-specific cell-mediated immune responses may decline. Such conditions allow a reactivation of latent VZV and result in a localized cutaneous rash erupting in a single dermatome called herpes zoster (HZ), or shingles. Patients with HZ involving the first division of the trigeminal nerve have a disease process termed herpes zoster ophthalmicus (HZO). HZO was described long ago by Hippocrates, but its relation to VZV was not elucidated until the advent of modern medical tools such as the immunohistochemical assays.

Herpesvirus simiae B virus

A type of herpesvirus which occurs in monkeys but can be transmitted to humans through bites or through contact with infected monkey tissue as in a laboratory situation. The virus infects the brain (encephalitis) and the surrounding membrane (meningitis).

Herpetic embryopathy

Transmission of the herpes virus from the mother to the baby during the fetal stage

Herpetic keratitis

A corneal inflammation due to a herpes virus - either herpes simplex or herpes zoster virus.

Keratitis is an inflammation of the cornea — the clear, dome-shaped tissue on the front of your eye that covers the pupil and iris. Keratitis is sometimes caused by an infection involving bacteria, viruses, fungi or parasites. Non-infectious keratitis can be caused by a minor injury, wearing your contact lenses too long or other noninfectious diseases.

Herrmann Opitz craniosynostosis

A very rare syndrome characterized mainly by mental retardation, skeletal abnormalities and an unusual facial appearance.

Herrmann syndrome

A rare disorder characterized by deafness, diabetes, kidney disease, brain dysfunction and muscle spasms.

Heterotaxy with polysplenia or asplenia

A rare genetic disorder characterized by the abnormal placement of internal organs as well as either the absence of the spleen or the presence of an extra spleen

Heterotaxy- visceral- X-linked

Heterotaxy ('heter' meaning 'other' and 'taxy' meaning 'arrangement'), or situs ambiguus, is a developmental condition characterized by randomization of the placement of visceral organs, including the heart, lungs, liver, spleen, and stomach. The organs are oriented randomly with respect to the left-right axis and with respect to one another (Srivastava, 1997). 30 PubMed Neighbors Heterotaxy is a clinically and genetically heterogeneous disorder. See also HTX2 (605376), caused by mutation in the CFC1 gene (605194) on chromosome 21; HTX3 (606325), which maps to 6q21; and HTX4, caused by mutation in the ACVR2B gene (602730).

HHV-6 encephalitis

A rare condition that usually occurs in immunocompromised people such as those undergoing transplants or HIV patients. The condition causes neurological symptoms.

Hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic skin disease characterized by recurrent, painful, boil-like lumps (nodules) under the skin. HS affects the areas around skin folds (e.g., armpits, groin, and breasts) and where apocrine glands (a form of sweat gland) and hair follicles are found. It is not contagious, but it is recurrent. It typically manifests as a single boil-like, pus-filled abscess or hard sebaceous lumps (lumps composed of sebum, or oil, which is excreted by the sebacous glands associated with hair follicles) and may progress to painful, deep-seated, inflamed clusters of lesions with chronic seepage involving significant scarring. In most cases, the cause of HS is unknown. It is likely that it results from a combination of genetic and environmental factors. Some cases of HS have been associated with specific genes, including NCSTN, PSEN1, and PSENEN. 
Hidradenitis suppurativa tends to start after puberty, persist for years and worsen over time. Early diagnosis and treatment can help manage the symptoms and prevent new lesions from developing.

Hillig syndrome

A very rare syndrome characterized mainly by mental retardation, large head, coarse face and reduced muscle tone.

Hip dislocation

A dislocated hip is a condition that can be congenital or acquired. Congenital hip dislocations are much more common in girls than in boys. Hip dislocations are relatively uncommon during athletic events.1 Injuries to small joints (eg, finger, wrist, ankle, knee) are much more common. However, serious morbidity can be associated with hip dislocations, making careful and expedient diagnosis and treatment important for the sports medicine physician.

Hip Dysplasia

A dislocation of the hip at birth or a hip joint that dislocates easily.