Clinical and genetic findings in patients with PHHI and SCHAD deficiency

PatientFS (ref. 14)IV-4 (this report and ref. 15)IV-7 (this report and ref. 13)
Gestation age38 weeks42 weeks40 weeks
Birth weight3.2 kg3.8 kg3.9 kg
Age when hypoglycemia was first diagnosed4 months3 days2 h*
Blood glucose at diagnosis1.4 mmol/l0.8 mmol/l1.6 mmol/l*
Plasma insulin (blood glucose)18 μU/ml (1.3 mmol/l)9.6 μU/ml (1.9 mmol/l)21 μU/ml (2.5 mmol/l)
Serum free fatty acids0.17 mmol/l0.31 mmol/l“Lower normal range”
Diazoxide-responsive hypoglycemiaYesYesYes
Concentration of 3-hydroxy- butyryl-carnitine in blood1.78 μmol/l0.93 μmol/l§1.09 μmol/l§
Presence of 3-hydroxyglutaric acid in urineYesYes§Yes§
Mutation in the HADHSC geneHomozygous C773T substitution in exon 7Homozygous deletion of CAGGTC at the exon 5 acceptor splice siteHomozygous deletion of CAGGTC at the exon 5 acceptor splice site
Predicted effect on the SCHAD proteinPro258Leu substitutionDeletion of amino acids 183–212Deletion of amino acids 183–212
  • *

    * Elective blood glucose was measured shortly after birth, treatment was started before symptoms of hypoglycemia appeared;

  • mean of 7 determinations;

  • mean of 3 determinations;

  • mean of 16 determinations;

  • §

    § determined as adults