Clinical application of massively parallel sequencing in the molecular diagnosis of glycogen storage diseases of genetically heterogeneous origin.
OBJECTIVE
Glycogen storage diseases are a group of inborn errors of glycogen synthesis or catabolism. The outcome for untreated patients can be devastating. Given the genetic heterogeneity and the limited availability of enzyme study data, the definitive diagnosis of glycogen storage diseases is made on the basis of sequence analysis of selected potentially causative genes.


METHODS
A massively parallel sequencing test was developed for simultaneous sequencing of 16 genes known to cause muscle and liver forms of glycogen storage diseases: GYS2, GYS1, G6PC, SLC37A4, GAA, AGL, GBE1, PYGM, PYGL, PFKM, PHKA2, PHKB, PHKG2, PHKA1, PGAM2, and PGM1. All the nucleotides in the coding regions of these 16 genes have been enriched with sufficient coverage in an unbiased manner.


RESULTS
Massively parallel sequencing demonstrated 100% sensitivity and specificity as compared with Sanger sequencing. Massively parallel sequencing correctly identified all types of mutations, including single-nucleotide substitutions, small deletions and duplications, and large deletions involving one or more exons. In addition, we have confirmed the molecular diagnosis in 11 of 17 patients in whom glycogen storage diseases were suspected.


CONCLUSIONS
This report demonstrates the clinical utility of massively parallel sequencing technology in the diagnostic testing of a group of clinically and genetically heterogeneous disorders such as glycogen storage diseases, in a cost- and time-efficient manner.
Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
Jing
J
Wang
Hong
H
Cui
Ni-Chung
NC
Lee
Wuh-Liang
WL
Hwu
Yin-Hsiu
YH
Chien
William J
WJ
Craigen
Lee-Jun
LJ
Wong
Victor Wei
VW
Zhang
D000293:Adolescent; D001483:Base Sequence; D002648:Child; D002675:Child, Preschool; D005260:Female; D018740:Genetic Heterogeneity; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D006008:Glycogen Storage Disease / Q000175:diagnosis* / Q000235:genetics*; D059014:High-Throughput Nucleotide Sequencing / Q000379:methods*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009154:Mutation; D016366:Open Reading Frames / Q000235:genetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity