scholarly journals Polymerase Chain Reaction, Nuclease Digestion, and Mass Spectrometry Based Assay for the Trinucleotide Repeat Status of the Fragile X Mental Retardation 1 Gene

2009 ◽  
Vol 81 (13) ◽  
pp. 5533-5540 ◽  
Author(s):  
Eric D. Dodds ◽  
Flora Tassone ◽  
Paul J. Hagerman ◽  
Carlito B. Lebrilla
Keyword(s):  
Mass Spectrometry ◽  
Polymerase Chain Reaction ◽  
Mental Retardation ◽  
Trinucleotide Repeat ◽  
Fragile X ◽  
Chain Reaction ◽  
Fragile X Mental Retardation ◽  
Nuclease Digestion ◽  
Polymerase Chain

A Novel Polymorphism in the FMR1 Gene: Implications for Clinical Testing of Fragile X Syndrome

2008 ◽  
Vol 132 (1) ◽  
pp. 95-98
Author(s):  
Bharat Thyagarajan ◽  
Matthew Bower ◽  
Michael Berger ◽  
Sidney Jones ◽  
Michelle Dolan ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Mental Retardation ◽  
Fragile X Syndrome ◽  
Southern Blot ◽  
Trinucleotide Repeat ◽  
Fragile X ◽  
Fmr1 Gene ◽  
Chain Reaction ◽  
Cgg Repeat ◽  
Polymerase Chain

Abstract Fragile X syndrome is the most common cause of inherited mental retardation among males. In most cases, the molecular basis of fragile X syndrome is the expansion and subsequent methylation of a CGG trinucleotide repeat in the 5′ untranslated region of the fragile X mental retardation 1 (FMR1) gene. Laboratory diagnosis usually relies on a combination of Southern blot and polymerase chain reaction analyses. In this case report we describe an unusual Southern blot result in a patient who presented with developmental delay and had a normal CGG repeat number by polymerase chain reaction analysis. Further investigation revealed a novel G3310C transversion in the FMR1 gene resulting in a new recognition site for the BssHII restriction enzyme. This novel restriction site could potentially mimic a partial deletion of the FMR1 gene on Southern blot analysis and thus represents a possible pitfall in the diagnosis of fragile X syndrome.

Mass spectrometry based trinucleotide repeat sequence detection using target fragment assay

2016 ◽  
Vol 8 (25) ◽  
pp. 5039-5044 ◽  
Author(s):  
Ting Zhang ◽  
Xiang-Cheng Lin ◽  
Hao Tang ◽  
Ru-Qin Yu ◽  
Jian-Hui Jiang
Keyword(s):  
Mass Spectrometry ◽  
Polymerase Chain Reaction ◽  
Trinucleotide Repeat ◽  
Repeat Sequence ◽  
Mass Spectrometry Detection ◽  
Chain Reaction ◽  
Sequence Detection ◽  
Magnetic Capture ◽  
Polymerase Chain ◽  
Acidic Degradation

A novel trinucleotide repeat length assay has been developed using magnetic capture and acidic degradation of target polymerase chain reaction amplicons followed by mass spectrometry detection.

scholarly journals 5′ UTR CGG repeat expansion in GIPC1 is associated with oculopharyngodistal myopathy

Brain ◽  
2020 ◽  
Author(s):  
Jianying Xi ◽  
Xilu Wang ◽  
Dongyue Yue ◽  
Tonghai Dou ◽  
Qunfeng Wu ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Trinucleotide Repeat ◽  
Late Onset ◽  
Age At Onset ◽  
Large Family ◽  
Repeat Expansion ◽  
Chain Reaction ◽  
Cgg Repeat ◽  
Sporadic Cases ◽  
Polymerase Chain

Abstract Oculopharyngodistal myopathy is a late-onset degenerative muscle disorder characterized by ptosis and weakness of the facial, pharyngeal, and distal limb muscles. A recent report suggested a non-coding trinucleotide repeat expansion in LRP12 to be associated with the disease. Here we report a genetic study in a Chinese cohort of 41 patients with the clinical diagnosis of oculopharyngodistal myopathy (21 cases from seven families and 20 sporadic cases). In a large family with 12 affected individuals, combined haplotype and linkage analysis revealed a maximum two-point logarithm of the odds (LOD) score of 3.3 in chromosomal region chr19p13.11-p13.2 and narrowed the candidate region to an interval of 4.5 Mb. Using a comprehensive strategy combining whole-exome sequencing, long-read sequencing, repeat-primed polymerase chain reaction and GC-rich polymerase chain reaction, we identified an abnormal CGG repeat expansion in the 5′ UTR of the GIPC1 gene that co-segregated with disease. Overall, the repeat expansion in GIPC1 was identified in 51.9% independent pedigrees (4/7 families and 10/20 sporadic cases), while the repeat expansion in LRP12 was only identified in one sporadic case (3.7%) in our cohort. The number of CGG repeats was <30 in controls but >60 in affected individuals. There was a slight correlation between repeat size and the age at onset. Both repeat expansion and retraction were observed during transmission but somatic instability was not evident. These results further support that non-coding CGG repeat expansion plays an essential role in the pathogenesis of oculopharyngodistal myopathy.

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