A 5 year old male was studied showing typical symptoms of Lesch-Nyhan syndrome: severe psychomotor retardation (inability to stand, walk, sit and speak) as well as choreic chronic movement and self-mutilation of fingers, lips and tongue. Uric acid was increased in serum, urine and spinal fluid. The activity of hypoxanthine-guanine phosphoribosyl transferase (HGPRT), as measured according to Cartier et al., was lower than 0.5% of controls, thus confirming the clinical diagnosis. The incorporation of 3H-hypoxanthine in phytohemagglutinin (PHA) stimulated and unstimulated lymphocytes was studied by autoradiography, according to De Bruyn. Culture of PHA stimulated lymphocytes was performed according to Morehead et al. Unstimulated lymphocytes from the patient did not show any incorporation, while 14.1 % of stimulated cells had a small number of grains. There is a statistically significant positive correlation (p <0.001) between size of stimulated cells and number of grains: the larger the cell the higher the number of grains. The presence of light labelling in the largest cells is interpreted as a demonstration of residual activity of HGPRT. Parents, sibs (one male and one female) as well as the maternal grandmother of the patient, showed heavy labelling in a high proportion of stimulated and unstimulated cells. While no statistically significant difference was found between cells of the father and brother of the patient, both are different (p <0.01) from those of the mother, sister and grandmother. Although these data seem to define the females studied as heterozygotes, this result must be accepted with caution as it has not been possible to obtain at the same time skin biopsy and assays of HGPRT in red cells.
|Translated title of the contribution||Lesch Nyhan syndrome: residual activity of hypoxanthine guanine phosphoribosyl transferase in stimulated lymphocytes|
|Number of pages||7|
|Journal||Rivista Italiana di Pediatria|
|Publication status||Published - 1977|
ASJC Scopus subject areas
- Pediatrics, Perinatology, and Child Health