Molecular diagnosis of mucopolysaccharidosis Type II (Hunter syndrome) by automated sequencing and computer-assisted interpretation: Toward mutation mapping of the Iduronate-2-sulfatase gene

Journal Article · Wed Mar 01 04:00:00 EST 1995 · American Journal of Human Genetics

OSTI ID:70437

Jonsson, J J; Aronovich, E L; Braun, S E; Whitley, C B ^[1]

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1. Univ. of Minnesota Medical School, Minneapolis, MN (United States)

Virtually all mutations causing Hunter syndrome (mucopolysaccharidosis type II) are expected to be new mutations. Therefore, as a means of molecular diagnosis, we developed a rapid method to sequence the entire iduronate-2-sulfatase (IDS) coding region. PCR amplicons representing the IDS cDNA were sequenced with an automatic instrument, and output was analyzed by computer-assisted interpretation of tracings, using Staden programs on a Sun computer. Mutations were found in 10 of 11 patients studied. Unique missense mutations were identified in five patients: H229Y (685{r_arrow}T, severe phenotype); P358R (1073C{r_arrow}G, severe); R468W (1402C{r_arrow}T, mild); P469H (1406C{r_arrow}A, mild); and Y523C (1568A{r_arrow}G, mild). Nonsense mutations were identified in two patients: R172X (514C{r_arrow}T, severe) and Q389X (1165C{r_arrow}T, severe). Two other patients with severe disease had insertions of 1 and 14 bp, in exons 3 and 6, respectively. In another patient with severe disease, the predominant (<95%) IDS message resulted from aberrant splicing, which skipped exon 3. In this last case, consensus sequences for splice sites in exon 3 were intact, but a 395C{r_arrow}G mutation was identified 24 bp upstream from the 3` splice of exon 3. This mutation created a cryptic 5` splice site with a better consensus sequence for 5` splice sites than the natural 5` splice site of intron 3. A minor population of the IDS message was processed by using this cryptic splice site; however, no correctly spliced message was detected in leukocytes from this patient. The mutational topology of the IDS gene is presented. 46 refs., 6 figs., 2 tabs.

• OSTI ID: 70437
• Journal Information: American Journal of Human Genetics, Journal Name: American Journal of Human Genetics Journal Issue: 3 Vol. 56; ISSN AJHGAG; ISSN 0002-9297
• Country of Publication: United States
• Language: English

Related Subjects

55 BIOLOGY AND MEDICINE
BASIC STUDIES
COMPUTER CODES
DIAGNOSTIC TECHNIQUES
DNA SEQUENCING
GENE MUTATIONS
GENES
GENETIC MAPPING
HEREDITARY DISEASES
HUMAN X CHROMOSOME
METABOLISM
MUCOPOLYSACCHARIDES
PATIENTS
PHENOTYPE
POLYMERASE CHAIN REACTION
TOPOLOGY