Glycerol kinase deficiency : follow-up during 20 years, genetics, biochemistry and prognosis.

• Departments of Clinical Chemistry and Transfusion Medicine, Sahlgrenska University Hospital, Göteborg University, Gothenburg, Sweden. Christina.Hellerud@clinchem.gu.seAIM: To follow two children with isolated glycerol kinase deficiency (GKD) with severe symptoms into adulthood. METHODS: The patients were followed during approximately 20 y and interviewed about symptoms, diet and physical activity. Fasting provocations, bicycle ergometer tests, dietary registrations, enzyme and mutation analysis were performed by standard protocols. RESULTS: The activity of glycerol kinase (GK) in fibroblasts was <10% of reference. One case had a deletion of exon 17, the other a mutation in exon 7 of the GK gene (601 A-->G). Both mothers were heterozygotes. Two maternal male cousins in one of the families were hemizygotes without symptoms. Tests performed in childhood documented pronounced sensitivity to fasting and physical exercise, whereas such tests at 23 and 31 y of age were essentially normal but with pronounced ketonaemia. After puberty, the boys had no hypoglycaemic symptoms and now report no problems with their condition; thus, their phenotype has changed over time. CONCLUSION: The greater importance of glycerol as a gluconeogenetic substrate in children than in adults may explain the episodes in young patients with GKD, often elicited by catabolic stress. With meals at frequent intervals, access to glucose and avoidance of strenuous sports, the prognosis is good for a normal adult life of a young child with isolated GKD and symptoms of hypoglycaemia.

Subject headings

MEDICIN OCH HÄLSOVETENSKAP  -- Hälsovetenskap -- Folkhälsovetenskap, global hälsa, socialmedicin och epidemiologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Health Sciences -- Public Health, Global Health, Social Medicine and Epidemiology (hsv//eng)

Keyword

Acetoacetates/urine

Adult

Child

Child; Preschool

Exons/genetics

Female

Follow-Up Studies

Genotype

Glycerol/blood/*urine

Glycerol Kinase/*deficiency/genetics/metabolism

Heterozygote

Humans

Male

Mutation

Pedigree

Phenotype

Prognosis

Publication and Content Type

ref (subject category)

art (subject category)