Warning: The NCBI web site requires JavaScript to function. more...
An official website of the United States government
The .gov means it's official. Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you're on a federal government site.
The site is secure. The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.
Acute intermittent porphyria
Acute intermittent porphyria (AIP), an autosomal dominant disorder, occurs in heterozygotes for an HMBS pathogenic variant that causes reduced activity of the enzyme porphobilinogen deaminase. AIP is considered "overt" in a heterozygote who was previously or is currently symptomatic; AIP is considered "latent" in a heterozygote who has never had symptoms, and typically has been identified during molecular genetic testing of at-risk family members. Note that GeneReviews does not use the term "carrier" for an individual who is heterozygous for an autosomal dominant pathogenic variant; GeneReviews reserves the term "carrier" for an individual who is heterozygous for an autosomal recessive disorder and thus is not expected to ever develop manifestations of the disorder. Overt AIP is characterized clinically by life-threatening acute neurovisceral attacks of severe abdominal pain without peritoneal signs, often accompanied by nausea, vomiting, tachycardia, and hypertension. Attacks may be complicated by neurologic findings (mental changes, convulsions, and peripheral neuropathy that may progress to respiratory paralysis), and hyponatremia. Acute attacks, which may be provoked by certain drugs, alcoholic beverages, endocrine factors, calorie restriction, stress, and infections, usually resolve within two weeks. Most individuals with AIP have one or a few attacks; about 3%-8% (mainly women) have recurrent attacks (defined as >3 attacks/year) that may persist for years. Other long-term complications are chronic renal failure, hepatocellular carcinoma (HCC), and hypertension. Attacks, which are very rare before puberty, are more common in women than men. Latent AIP. While all individuals heterozygous for an HMBS pathogenic variant that predisposes to AIP are at risk of developing overt AIP, most have latent AIP and never have symptoms. [from GeneReviews]
Encephalopathy, porphyria-related
Porphyria-related encephalopathy (ENCEP) is an autosomal recessive disorder characterized by the onset of progressive neurologic abnormalities in early infancy. Features include global developmental delay, poor walking or inability to walk, impaired intellectual development, hypotonia, ataxia, dysarthria, spasticity, ocular abnormalities, and peripheral neuropathy. The disease course is usually rapidly progressive and may lead to death in childhood. Laboratory studies show increased plasma and urinary levels of the putatively neurotoxic porphyrin precursors delta-aminolevulinic acid (ALA), porphobilinogen (PBG), and uroporphyrin resulting from deficient HMBS enzymatic activity (Solis et al., 2004). [from OMIM]
Filter your results:
Your browsing activity is empty.
Activity recording is turned off.
Turn recording back on