Histidinemia is a rare hereditary metabolic disorder
characterized by a deficiency of the enzyme histidase, which is necessary
for the metabolism of the amino acid histidine. The majority of individuals
Histidase Deficiency Syndrome; Histidine Ammonia-Lyase
Deficiency; HAL Deficiency; HIS Deficiency; Hyperhistidinemia.
Histidinemia is inherited as an
autosomal recessive trait and is considered one of the most common inborn
errors of metabolism. It is present at birth and affects males and females
in equal numbers. It is now thought to be a primarily benign disorder. In a
study of more than 20 million newborns, the incidence of this disease was
estimated to be 1:11,500 births. This medical condition seems to be most
prevalent among people of French Canadian or Japanese descent. In the
Province of Quebec, Canada, the incidence is estimated approximately 1:8600
infants. In Japan, the incidence is reported to be 1:9500 infants in Japan.
Histidinemia is considered a benign condition.
For years, it was believed that mental retardation and speech defects were
associated with histidinemia; however, it has now been established that
these findings are coincidental. Infants with histidinemia are asymptomatic.
Individuals with histidinemia have elevated levels of the amino acid
histidine in the blood and excessive amounts of histidine, imidazole pyruvic
acid, and other imidazole metabolism products in the urine.
No specific anesthetic considerations
with this medical conditions.
Histidinuria as A Result of Renal Tubular Defect: Disorder
characterized by mild mental retardation and histidinuria despite normal
blood levels. Histidine loading showed impaired intestinal absorption.
Clinical findings include myoclonic seizures, sensorineural deafness, thin
upper lips and long shallow philtrum, and short thick fingers and toes.
Radiologically, the middle phalanges are short, rounded, and abnormally
shaped. The inheritance is presumably autosomal recessive transmission.
Lam WK, Cleary MA, Wraith JE, et al: Histidinemia: A benign metabolic
disorder. Arch Dis Child 74:343 346, 1996.
Lemieux B: Newborn urine screening experience with over one million infants
in the Quebec network of genetic medicine. J Inherit Metab Dis