title: Clinical heterogeneity and molecular findings in five Polish patients with glycerol kinase deficiency: investigation of two splice site mutations with computerized splice junction analysis and Xp21 gene-specific mRNA analysis.
abstract: Five cases of glycerol kinase deficiency are presented with clinical, biochemical, and genetic results. Two had the glycerol kinase deficiency as part of an Xp21 contiguous gene deletion syndrome-complex form-and three had an isolated form of the enzyme deficiency. In these we found two splice site mutations (IVS1+4A>G, IVS9-1G>T) and one insertion (1393_1394insG). In patients with the complex form, a deletion of the DAX1, GK genes and the distal part of the DMD gene was found. A computerized study was performed to predict the effects of the splice site mutations. It showed that the IVS9-1G>T mutation substantially altered and removed the wild-type site and enhanced a cryptic site seven nucleotides downstream, and that the IVS1+4A>G diminished the strength of the wild-type donor site from strong to leaky. To verify these predictions, we developed an RT-PCR system with gene-specific primers that exclusively amplifies the Xp21 glycerol kinase gene transcript. Identification of individuals at risk is motivated by a need to avoid delay in a correct diagnosis. For reliable identification of heterozygotes for isolated glycerol kinase deficiency, knowledge of the specific mutation in the proband is required. This is easily obtained with the RT-PCR analyses developed in this study.
authors.affiliation: Department of Clinical Chemistry and Transfusion Medicine, Sahlgrenska University Hospital, Göteborg University, Bruna Stråket 16, S 413 415 Gothenburg, Sweden. Christina.Hellerud@clinchem.gu.se
authors.forename: Christina
authors.initials: C
authors.lastname: Hellerud
authors.forename: Maciej
authors.initials: M
authors.lastname: Adamowicz
authors.forename: Dorota
authors.initials: D
authors.lastname: Jurkiewicz
authors.forename: Joanna
authors.initials: J
authors.lastname: Taybert
authors.forename: Jolanta
authors.initials: J
authors.lastname: Kubalska
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Ciara
authors.forename: Ewa
authors.initials: E
authors.lastname: Popowska
authors.forename: James R
authors.initials: JR
authors.lastname: Ellis
authors.forename: Sven
authors.initials: S
authors.lastname: Lindstedt
authors.forename: Ewa
authors.initials: E
authors.lastname: Pronicka
mesh_terms: D000309:Adrenal Insufficiency / Q000235:genetics; D041321:Chromosomes, Human, X; D057137:DAX-1 Orphan Nuclear Receptor; D004252:DNA Mutational Analysis; D017931:DNA Primers / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000172:deficiency / Q000235:genetics; D017353:Gene Deletion; D005990:Glycerol / Q000097:blood / Q000652:urine; D005991:Glycerol Kinase / Q000737:chemistry / Q000172:deficiency / Q000235:genetics*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008969:Molecular Sequence Data; D020388:Muscular Dystrophy, Duchenne / Q000235:genetics; D009154:Mutation; D011044:Poland; D018807:Polymorphism, Single-Stranded Conformational; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018168:Receptors, Retinoic Acid / Q000737:chemistry / Q000172:deficiency / Q000235:genetics; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods
chemical_list: D057137:DAX-1 Orphan Nuclear Receptor; D017931:DNA Primers; D004268:DNA-Binding Proteins; C539965:NR0B1 protein, human; D012333:RNA, Messenger; D018168:Receptors, Retinoic Acid; D012097:Repressor Proteins; D005991:Glycerol Kinase; D005990:Glycerol