GroupPresentingHPOs: HP:0001324, HP:0001270, HP:0002205, HP:0002098, HP:0001635, HP:0001640, HP:0011968
HPOsFreeText: IOPD, reduced GAA activity, paucity of movements
GroupNotHPOs:
NumberMales: 14
NumberFemales: 11
CountryOrigin: mainland China; 12 patients from southern China, 13 from northern China
Ethnicity: Chinese
Race: Chinese
AgeRange: median age at symptom onset = 3.4mo, median age at diagnosis = 4.9mo
TotalNumber: 25
FamilyInfo: Parents of those individuals with mutations were sequenced
NoFamily: n/a
GroupAddInfo: all patients diagnosed with IOPD between 2013 and 2016 at Shanghai Children's Medical Center. Of the 24 untreated patients, non survived beyond 1.5yrs, only surviving (Patient 25) was 7mo at last follow-up.
GroupPreviousTesting: IOPD diagnosed via reduced GAA enzyme activity in leukocytes or DBS (PMID: 16702880)
GroupGenotypingMethod: DNA isolated from blood samples, coding exons (2-20) and intron/exon boundaries of GAA gene amplified via PCR (primers: PMID: 10338092), resulting DNA was sequenced with ABI3730XL sequencer then was analyzed with Mutation Survey or DNA Variant Analysis software, novel mutations were screened in 60 normal individuals (120 alleles) via direct sequencing and no novel variants were found among these suggesting those found in study patients are uncommon polymorphisms.
fragments containing a mutation in the patients were amplified and sequenced for the corresponding parents
Phylogenetic conservation of missense mutations analyzed with ClustalX program, and pathogenicity of novel variants predicited with MutationTaster, sorting intolerant from tolerant (SIFT), and PolyPhen-2
Variant: NM_000152.4(GAA):c.2662G>T (p.Glu888Ter)
this was identified (by present study) as the most common variant in northern Chinese patients, heterozygous for 5 patients, homozygous for one patient
ClinVar: 578595, https://www.ncbi.nlm.nih.gov/clinvar/variation/578595/
gnomAD: 1.65e-05, http://exac.broadinstitute.org/variant/17-78092467-G-T