Practical difficulties in the diagnosis of transient non-ketotic hyperglycinaemia.

Making a diagnosis of transient non-ketotic hyperglycinaemia (tNKH) can be difficult. We report an infant who presented in the neonatal period with symptoms of NKH. Metabolic studies performed on day 2 of life showed raised cerebrospinal fluid (CSF) and plasma glycine, and a CSF:plasma glycine ratio consistent with NKH; however, a liver biopsy performed on day 5 revealed normal liver glycine cleavage system activity. Subsequently, the child's clinical condition improved in the absence of any therapeutic medication. Clinical assessment and developmental follow-up at 5 months, 1 year, and 2 years were age-appropriate. Guidance for the investigation and management of future suspected cases of tNKH is discussed.

Mild ichthyosis in a 4-year-old boy with multiple sulphatase deficiency.

We report a 4-year-old boy with multiple sulphatase deficiency (MSD). His early health was good. By the end of his first year there were concerns about developmental delay but by 26 months he showed clear evidence of regression in that he was barely able to sit unsupported and had lost all fine motor and communication skills. At that time he also had widespread mild ichthyosis that cleared completely with the use of emollients. The neurological deterioration suggested a diagnosis of metachromatic leucodystrophy, and a reduction in the leucocyte arylsulphatase A activity was detected. The ichthyosis suggested steroid sulphatase deficiency, and a reduction in the leucocyte steroid sulphatase activity was detected. The enzyme deficiency was much less marked for steroid sulphatase than for arylsulphatase A in this boy. This diversity in enzyme activities is typical of MSD and correlates with the mild ichthyosis in this child. This case shows that even mild ichthyosis should prompt measurement of steroid sulphatase activity in a child of either sex with unexplained neurological deterioration.

Prenatal diagnosis of succinate semialdehyde dehydrogenase deficiency in non-identical twins.

Prenatal diagnosis was performed by both DNA and enzymatic analysis on non-identical twins conceived by in vitro fertilization and at risk of succinate semialdehyde dehydrogenase deficiency. One fetus was predicted to be affected and one unaffected and selective fetal reduction was performed.

Mutation screening for tyrosinaemia type I.

This study reports the development of a mutation screening strategy for tyrosinaemia type I, and the identification of six novel mutations in the FAA gene.