Serinedeficiëntie

Serine-synthesis disorders have recently been described as a new group of inborn errors of metabolism due to a deficiency of the amino acid serine. Until now two defects have been reported, first 3-fosfoglycerate dehydrogenase (3-PGDH) deficiency and secondly 3-fosfoserine phosphatase (3-PSP) deficiency. Both disorders present with congenital microcephaly, severe psychomotor retardation and in 3-PGDH intractable seizures. Disorders of serine synthesis are potentially treatable disorders and the first results of serine supplementation are very promising. The biochemical diagnosis is based on the detection of low concentrations of serine and to a variable extend of glycine in fasted plasma samples or cerebrospinal fluid. For those involved in the biochemical diagnosis of inborn errors, low concentrations of amino acids should be alarming to the same extend as high concentrations.