Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024312 (lymphopenia)
 4,859 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Deficiency of purine nucleoside phosphorylase (PNP) was detected in a 3-yr-old boy who was admitted for investigation of a behavior disorder and spastic diplegia. The urinary excretion of purines, analyzed by high-performance liquid chromatography, showed the presence of large amounts of (deoxy)inosine and (deoxy)guanosine and low uric acid levels. Analysis of the (deoxy)nucleotide pools of erythrocytes showed elevated levels of deoxyguanine nucleotides and NAD and decreased guanine nucleotides. PNP activity in red blood cells was 0.1-0.5% of normal on two occasions and undetectable on four later measurements. Furthermore no immunoreactive material could be detected in his red cell lysate using an anti-PNP antiserum. PNP activities in the red cells of the patient's parents were 35 and 50% of normal. The presence of (minor) residual PNP activity in the patient enabled the investigation of some enzyme properties after partial purification. No abnormalities could be detected in substrate affinity for inosine, heat stability, and electrophoretic properties. In the heterozygous parents no signs of a mutant enzyme could be found. The molecular specific activities of the parental enzymes were also normal, indicating that no immunoreactive material attributable to inactive-mutant enzyme subunits was present. A striking feature of the patient is the prevailing neurologic abnormalities presumably caused by the metabolic disorder. A severe lymphopenia exists; however, clinical symptoms of an immune deficiency did not become apparent until the age of 4 yr.
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PMID:A new case of purine nucleoside phosphorylase deficiency: enzymologic, clinical, and immunologic characteristics. 310 87

Purine nucleoside phosphorylase (PNP) deficiency is a rare autosomal recessive metabolic disorder that results in combined immunodeficiency, neurologic dysfunction and autoimmunity. PNP deficiency has never been reported from Saudi Arabia or in patients with an Arabic ethnic background. We report on two Saudi girls with PNP deficiency. Both showed severe lymphopenia and neurological involvement. Sequencing of the PNP gene of one girl revealed a novel missense mutation Pro146>Leu in exon 4 due to a change in the codon from CCT>CTT. Expression of PNP (146L) cDNA in E coli indicated that the mutation greatly reduced, but did not completely eliminate PNP activity.
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PMID:Purine nucleoside phosphorylase deficiency in two unrelated Saudi patients. 1958 74