Lowe syndrome is a rare handicapping disorder inherited in an X-linked recessive manner. Affected males are severely mentally retarded, visually handicapped (due to congenital cataracts and sometime glaucoma) and have aminoaciduria often with secondary rickets. The underlying biochemical abnormality is unknown and the diagnosis remains a clinical one.
To estimate the prevalence and natural history of the condition in the British Isles
Using Cytogenic and DNA techniques - to attempt to map the Lowe syndrome gene on the X chromosome
Males with
a) congenital cataracts and/or glaucoma
and
b) aminoaciduria
and
c) mental retardation
Females with the same features who may have Turner syndrome or an X chromosome abnormality.
In the course of the study, 27 confirmed cases were identified in the UK and the natural history of the 26 children in whom there were adequate data is presented. The 26 comprise one girl and 25 boys. 15 are familial cases from 10 families, and the remaining 10 are isolated cases. Clinical data was analysed separately for the two groups but the only differences found related to early investigation and diagnosis. The clinical course was the same in the two groups
Ages ranged from 7 months to 32 years. Birth weight was normal but subsequent growth was poor particularly after the first year. Even boys who had optimally correct renal tubular acidosis remained well below the 3rd centile for height. Weight was relatively less affected and head circumference remained in the normal range. A consistent pattern of dysmorphic features emerged which became more pronounced with age.
Of the 15 boys over 10 years of age, 11 had learned to walk (through 3 subsequently lost this ability as a complication of rickets). Only 4 were able to hold a conversation and only 2 were completely continent. 9 had seizures, 7 had significantly useful vision. Skeletal problems were common secondary to hypotonia and rickets: 6 had fractures, 6 had scoliosis and 12 had other bone deformities.
In all familial cases pedigrees were consistent with X-linked recessive inheritance. The one girl had a balanced reciprocal translocation between the X and 9 chromosomes.