The Lowe syndrome. Clinical findings and the detection of a gene mutation in a 4-year old boy

Cardial features of the oculocerebrorenal syndrome of Lowe (OCRL) are congenital cataract, mental retardation, hypotonia and renal tubular dysfunction. The primary biochemical defect remains unknown. An inborn error of the inositol phosphate metabolism as a result of mutations within the OCRL gene localized on the X-chromosome is discussed. Because of the medical history (congenital cataract, conspicuous family history) and the presenting symptoms (typical facies, muscular hypotonia, mental retardation, tubular dysfunction with metabolic acidosis) the clinical diagnosis of the lowe syndrome was made in a 4-year-old-boy. In the mother lens opacities indicated the carrier status of this syndrome. Analysing the DNA for a mutation a guanine-adenine-transition was detected that was localized at the splice-junction region of the exon next to the last. In the mother this mutation was detected in a heterozygous pattern. Discussion: The mutation detected is the molecular cause of the symptoms in our patient with Lowe syndrome. Because of the special localisation of this mutation it is possible, that the mutation causes an exchange of an amino acid or an uncorrect removal of the exon, or a shifting of the encoding nucleotide sequence.