Abstract:

Objective To investigate the clinical characteristics and genetic variations of two children with isolation glycerol kinase deficiency (GKD), fthereby enhancing clinicians' understanding of this the disease. Methods Clinical and genetic data were collected from two pediatric patients with isolated GKD admitted between March 2018 and December 2023.Their clinical manifestations and genetic variation profiles were analyzed systematically. Results Both patients were male. Patient 1 aged 6 years and 7 months, exhibited paroxysmal nausea, vomiting, abdominal pain, anorexia, and lethargy. Laboratory findings revealed recurrent hypoglycemia, metabolic acidosis, elevated blood ketone bodies and triglycerides, as well as increased urinary ketone bodies and glycerol concentrations. Patient 2 aged 3 months,experienced asphyxia, seizures, coma, and feeding difficulties shortly after birth, leading to hospitalization for brain injury assessment. Elevated blood triglycerides and increased urinary glycerol concentrations were detected.. The whole exon gene detection showed that there was a hemizygous variation c.1145C>T (p.A382V) in Exon 15 of GK gene in patient 1, and a hemizygous variation c.422C>G (p.T141R) in Exon 6 of GK gene in patient 2. Sanger sequencing confirmed that both the c.1145C>T and c.422C>G variants were from phenotypically normal mothers and classified as variants of uncertain significance according to the ACMG guidelines, with no prior reports. Conclusion The acute-phase symptoms of isolated GKD lack specificity. Elevated blood triglycerides and urinary glycerol concentrations can aid in diagnosis, while definitive diagnosis relies on GK gene testing.

Key words: glycerol kinase deficiency, hypoglycemia, GK gene, triglycerides, child