This study was performed to investigate 1) technical modification of Guthrie method for mass screening to detect
histidinemia, 2) patients with
histidinemia in view of genetic and biochemical aspects, and 3)
therapy of
histidinemia in newborn infants. Guthrie method was the useful method for mass screening of
histidinemia in newborn infants. It is possible to measure blood level of
histidine using by Subutilis spore ATTCC 6633 instead of ATCC 6051. Mass screening of
histidinemia was done in about 20,000 newborn infants in Hokkaido, and one case of
histidinemia, which was first case in Japan found by this method, was observed. In a case of 5 year-old boy with clinical
histidinemia, in whom serum
histidine level was 12.1 mg/kl,
histidase activity of stratum corneum was not detectable,
FIGLU and
urocanic acid in urine and
urocanic acid in sweat were not detected, the half life of
histidine at intravenous
histidine loading test was too long to measure. But in other case of 13 year-old boy without clinical signs of
histidinemia, elder brother of former case, serum
histidine level was 4.7 mg/dl,
histidase activity was 11% of normal control, excretion of
FIGLU and
urocanic acid in urine, and
urocanic acid in sweat were observed, and the half life of
histidine was 5 hours and 50 minutes (normal: 2 hours and 20 minutes). In both cases,
Tryptophan absorption and metabolism were not influenced by high level of blood
histidine.
Therapy with low
histidine milk was made in 3 cases of affected infants. When
histidine was given orally in dose of 30-35 mg/kg/day, serum
histidine level was down to 3-5 mg/dl in a week in all cases, but in one case low proteinemia an
anemia were observed. When
histidine was orally given in a dose of 40-50 mg/kg/day, serum
histidine level was well controlled. In all cases with
histidine limited diets,
mental retardation and growth retardation were not found.