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Orphanet References OMIM Gene GeneReviews HGMD HGNC
last update : 6/07/2006
Symbol HAL
Location 12q22-q23.1
Name histidinemia
Other name(s) histidine ammonia-lyase deficiency
Corresponding gene HAL
Main clinical features
  • mental retardation and speech difficulties, with elevated histidine in body fluids and decreased urocanic acid in blood and skin
  • Genetic determination autosomal recessive
    Function/system disorder metabolism/aminoacids
    Type disease
    Gene product
    Name histidine ammonia lyase, histidase (HAL)
    Gene mutationChromosome rearrangementEffectComments
    missense   abnormal protein/loss of function R322P and P259L