Molecular characterization of the PK‐LR gene in pyruvate kinase deficient Spanish patients

Abstract

The PK‐LR gene has been studied in 12 unrelated patients with red cell pyruvate kinase deficiency and hereditary nonspherocytic haemolytic anaemia (CNSHA). The entire codifying region of the R‐type PK gene and the flanking intronic regions were analysed by single‐stranded conformation polymorphism (SSCP) followed by direct sequencing of abnormal DNA. 10 different mutations were identified in 22/24 alleles at risk. Eight of these were missense mutations that caused the following single amino acid changes: G514C (172Glu‐Gln), G1010A (337Arg‐Gln), G1015C (339Asp‐Gln), T1070C (357Ile‐Thr), C1223T (408Thr‐Ile), G1291A (431Ala‐Thr), C1456T (486Arg‐Trp) and G1595A (532Arg‐Gln). Two were nonsense mutations: G721T (241Glu‐Stop) and C1675T (559Arg‐Stop). 7/22 alleles demonstrated the same C1456→ T mutation. The study of the polymorphic site at nucleotide (nt) 1705 performed in all cases disclosed a 1705 C/C mutation in 10 and a 1705 A/C mutation in three. This is the first report on the presence of several different L‐type PK gene mutations within Spanish population. Furthermore, from the PK gene mutations found, six were unique and not previously described (1015C, 1070C, 1223T, 1291A, 1595A and 1675T) and one (C1456T) seems to be predominant in Spain. Interestingly, no case with the 1529A mutation commonly found in Northern European populations was present here.

Red cell pyruvate kinase deficiency: molecular and clinical aspects

“…Each of these mutations is found in the context of its own haplotype, arguing that each has a unique origin. Other mutations, in particular 721T and 994A, are present with a lower frequency in White people (Baronciani & Beutler, 1993; Zarza et al , 1998; Fermo et al , 2005). Only two mutations (1151T, 1436A) are common to Japanese and White populations.…”

Eight novel mutations and consequences on mRNA and protein level in pyruvate kinase-deficient patients with nonspherocytic hemolytic anemia

“…In PKD, 9 nonsense mutations, 10 frameshift mutations, and 12 splice site mutations have been identified [Baronciani et al, 1998;Zarza et al, 1998;Manco et al, 1999], of which only three have been analyzed at the cDNA level [Kanno et al, 1997]. In this study, we describe three such mutations of the human PKLR gene associated with PKD.…”

“…This substantiates the hypothesis of a common ancestor gene for this mutation. Recent data suggest regional differences, with a Northern/Western European and US Caucasian prevalence of the 1529G→A and a Southern European prevalence of the 1456C→T mutation [Lenzner et al, 1997;Zanella et al, 1997;Zarza et al, 1998;Manco et al, 1999]. Interestingly, in patient 6 the 1456T mutation was found both with the 15 or the 16 ATT repeat rather than the 14 ATT repeat usually observed.…”

“…Apparently, in most cases PKD is caused by the production of mutant enzymes with abnormal biochemical characteristics. To date, at the nucleotide level a total of 125 mutations have been reported in the PKLR gene [Baronciani et al, 1998;Zarza et al, 1998;Manco et al, 1999].…”

Spectrum of novel mutations in the human PKLR gene in pyruvate kinase‐deficient Indian patients with heterogeneous clinical phenotypes

“…In contrast, G6PD deficiency affects millions of individuals worldwide (23). The 1456C.T mutation is also common in southern Europe (29% in Italy, 32% in Spain, and 35% in Portugal) (25)(26)(27), while the 1529G.A mutation is the most common one in the USA (42%) (28) and in northern and central Europe (41%). After excluding other common causes like thalassaemia, sickle-cell anaemia, HS, G6PD deficiency and autoimmune haemolytic anaemia, these cases were investigated for various enzymopathies (24).…”