Rare Tautomers of Artificially Expanded Genetic Letters and their Effects on the Base pair Stabilities

SummarySevere Glanzmann's thrombasthenia is relatively frequent in Iraqi-Jews and Arabs residing in Israel. We have recently described the mutations responsible for the disease in Iraqi-Jews – an 11 base pair deletion in exon 12 of the glycoprotein IIIa gene, and in Arabs – a 13 base pair deletion at the AG acceptor splice site of exon 4 on the glycoprotein IIb gene. In this communication we show that the Iraqi-Jewish mutation can be identified directly by polymerase chain reaction and gel electrophoresis. With specially designed oligonucleotide primers encompassing the mutation site, an 80 base pair segment amplified in healthy controls was clearly distinguished from the 69 base pair segment produced in patients. Patients from 11 unrelated Iraqi-Jewish families had the same mutation. The Arab mutation was identified by first amplifying a DNA segment consisting of 312 base pairs in controls and of 299 base pairs in patients, and then digestion by a restriction enzyme Stu-1, which recognizes a site that is absent in the mutant gene. In controls the 312 bp segment was digested into 235 and 77 bp fragments, while in patients there was no change in the size of the amplified 299 bp segment. The mutation was found in patients from 3 out of 5 unrelated Arab families. Both Iraqi-Jewish and Arab mutations were detectable in DNA extracted from blood and urine samples. The described simple methods of identifying the mutations should be useful for detection of the numerous potential carriers among the affected kindreds and for prenatal diagnosis using DNA extracted from chorionic villi samples.

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Mutation Spectrum in Patients with Wiskott-Aldrich Syndrome and X-linked Thrombocytopenia: Identification of Twelve Different Mutations in the WASP Gene

Thrombosis and Haemostasis ◽

10.1055/s-0038-1650318 ◽

1996 ◽

Vol 75 (04) ◽

pp. 546-550 ◽

Cited By ~ 21

Author(s):

Marianne Schwartz ◽

Albert Békássy ◽

Mikael Donnér ◽

Thomas Hertel ◽

Stefan Hreidarson ◽

...

Keyword(s):

Base Pair ◽

Hot Spot ◽

Missense Mutations ◽

Nucleotide Substitutions ◽

Exon 2 ◽

Wiskott Aldrich Syndrome ◽

Base Pair Deletion ◽

Reliable Diagnosis ◽

Wasp Gene ◽

Detection Of Mutations

SummaryTwelve different mutations in the WASP gene were found in twelve unrelated families with Wiskott-Aldrich syndrome (WAS) or X-linked thrombocytopenia (XLT). Four frameshift, one splice, one nonsense mutation, and one 18-base-pair deletion were detected in seven patients with WAS. Only missense mutations were found in five patients diagnosed as having XLT. One of the nucleotide substitutions in exon 2 (codon 86) results in an Arg to Cys replacement. Two other nucleotide substitutions in this codon, R86L and R86H, have been reported previously, both giving rise to typical WAS symptoms, indicating a mutational hot spot in this codon. The finding of mutations in the WASP gene in both WAS and XLT gives further evidence of these syndromes being allelic. The relatively small size of the WASP gene facilitates the detection of mutations and a reliable diagnosis of both carriers and affected fetuses in families with WAS or XLT.

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