Klinická a genetická heterogenita je charakteristickým rysem mnohočetného myelomu (MM) a navzdory intenzivnímu úsilí o porozumění patogenezi MM, zůstává řada procesů zahrnutá ve vývoji MM neobjasněna. Nové metodologické přístupy, jako je studium profi lů genové exprese (GEP), jsou vhodným nástrojem spojujícím klinické výstupy (odpověď na léčbu a přežití) s molekulární a genetickou variabilitou onemocnění. Hlavním úkolem je nyní defi novat diagnostický a prognostický význam GEP technologie v klinickém praxi.
Clinical and genetic heterogeneity is a characteristic feature of multiple myeloma (MM). Despite intensive efforts to clarify the pathogenesis of MM, mechanisms of MM development remain enigmatic. Novel methodological approaches, such as gene expression profi ling (GEP), are valuable tools in order to link clinical endpoints, such as response to treatment and surfoval, with th molecular and genetic heterogenity of the disease. The main challenge of current studies is to defi ne diagnostic and prognostic relevance of GEP technologies in a clinical management.
- MeSH
- Gene Expression * MeSH
- DNA, Complementary analysis MeSH
- Humans MeSH
- RNA, Messenger analysis MeSH
- Microarray Analysis * methods MeSH
- Multiple Myeloma * genetics physiopathology MeSH
- Oligonucleotide Array Sequence Analysis MeSH
- Check Tag
- Humans MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
- MeSH
- Adenylosuccinate Lyase genetics deficiency MeSH
- Child MeSH
- Phenotype MeSH
- Cloning, Molecular MeSH
- DNA, Complementary analysis biosynthesis MeSH
- Humans MeSH
- Mutation MeSH
- Central Nervous System Diseases enzymology pathology MeSH
- Child, Preschool MeSH
- Check Tag
- Child MeSH
- Humans MeSH
- Child, Preschool MeSH
Human beta-mannosidosis is an autosomal recessive, lysosomal storage disease caused by a deficiency of the enzyme beta-mannosidase. Unlike the severe clinical manifestation of the disease in ruminants, in which it leads to neonatal death, the human disease phenotype is generally milder. In addition, the phenotypic manifestation among the reported cases of human beta-mannosidosis is variable, even among members of the same family. To understand the molecular basis of the human disease and the mechanisms for such clinical variability, we sequenced the entire coding region of the human beta-mannosidase gene using a combination of cDNA library screening, RT-PCR and 5' rapid amplification of cDNA ends (RACE). The composite cDNA is 3293 nt, consisting of an 87 nt 5'-untranslated region, 2640 nt coding region and 566 nt 3'-untranslated region. The gene was localized to human chromosome 4q22-25. Analysis of a multiple tissue northern blot demonstrated a single 3.7 kb transcript. Mutation analysis of a Czech gypsy family with two siblings differently affected with beta-mannosidosis demonstrated a homozygous A-->G transition 2 bp upstream of a splice acceptor site. The associated cryptic splice site activation and exon skipping caused by this mutation resulted in two abnormally spliced mutant mRNA species in both siblings.
- MeSH
- alpha-Mannosidosis * genetics MeSH
- beta-Mannosidase MeSH
- DNA, Complementary analysis genetics MeSH
- Humans MeSH
- Mannosidases * genetics MeSH
- Molecular Sequence Data MeSH
- Mutation * MeSH
- Amino Acid Sequence MeSH
- Base Sequence MeSH
- Sequence Analysis MeSH
- Sequence Alignment MeSH
- Check Tag
- Humans MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
- Research Support, U.S. Gov't, P.H.S. MeSH
We have shown previously that a variant allele of the short-chain acyl-CoA dehydrogenase ( SCAD ) gene, 625G-->A, is present in homozygous form in 7% of control individuals and in 60% of 135 patients with elevated urinary excretion of ethylmalonic acid (EMA). We have now characterized three disease-causing mutations (confirmed by lack of enzyme activity after expression in COS-7 cells) and a new susceptibility variant in the SCAD gene of two patients with SCAD deficiency, and investigated their frequency in patients with elevated EMA excretion. The first SCAD-deficient patient was a compound heterozygote for two mutations, 274G-->T and 529T-->C. These mutations were not present in 98 normal control alleles, but the 529T-->C mutation was found in one allele among 133 patients with elevated EMA excretion. The second patient carried a 1147C-->T mutation and the 625G-->A polymorphism in one allele, and a single point mutation, 511C-->T, in the other. The 1147C-->T mutation was not present in 98 normal alleles, but was detected in three alleles of 133 patients with elevated EMA excretion, consistently as a 625A-1147T allele. On the other hand, the 511C-->T mutation was present in 13 of 130 and 15 of 67 625G alleles, respectively, of normal controls and patients with elevated EMA excretion, and was never associated with the 625A variant allele. This over-representation of the haplotype 511T-625G among the common 625G alleles in patients compared with controls was significant ( P < 0.02), suggesting that the allele 511T-625G-like 511C-625A-confers susceptibility to ethylmalonic aciduria. Expression of the variant R147W SCAD protein, encoded by the 511T-625G allele, in COS-7 cells showed 45% activity at 37 degrees C in comparison with the wild-type protein, comparable levels of activity at 26 degrees C, and 13% activity when incubated at 41 degrees C. This temperature profile is different from that observed for the variant G185S SCAD protein, encoded by the 511C-625A allele, where higher than normal activity was found at 26 and 37 degrees C, and 58% activity was present at 41 degrees C. These results corroborate the notion that the 511C-625A variant allele is one of the possible underlying causes of ethylmalonic aciduria, and suggest that the 511C-->T mutation represents a second susceptibility variation in the SCAD gene. We conclude that ethylmalonic aciduria, a commonly detected biochemical phenotype, is a complex multifactorial/polygenic condition where, in addition to the emerging role of SCAD susceptibility alleles, other genetic and environmental factors are involved.
- MeSH
- Acyl-CoA Dehydrogenase MeSH
- Acyl-CoA Dehydrogenases genetics deficiency MeSH
- Alleles MeSH
- COS Cells MeSH
- Fibroblasts metabolism MeSH
- Gene Frequency MeSH
- Infant MeSH
- DNA, Complementary analysis MeSH
- Cells, Cultured MeSH
- Humans MeSH
- Malonates * urine MeSH
- Mutation MeSH
- Infant, Newborn MeSH
- Temperature MeSH
- Blotting, Western MeSH
- Animals MeSH
- Check Tag
- Infant MeSH
- Humans MeSH
- Male MeSH
- Infant, Newborn MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Case Reports MeSH
- Research Support, Non-U.S. Gov't MeSH
