PatientF1P4: Male, birth onset, prenatal diagnosis, Caucasian

HPOsFreeText: IOPD was confirmed with decreased acid GAA on a lymphocyte assay (6 nmol/hr/mg, control 36 nmol/hr/mg) and on a foreskin fibroblast sample,

CaseAddInfo: First cousin twice removed of F1P1, Mother carries both c.1880C>T and VUS c.1642G>T mutations in cis

PatientF1P1: Female, 30 years onset, 40 years diagnosis, Caucasian

CasePresentingHPOs: HP:0007340, HP:0002172 (Leg weakness, Postural instability)

HPOsFreeText: History of hyperCKemia greater than 1,000 U/L (control 30–220 U/L), Showed deficient muscle acid GAA activity (0.05 µmol/min/g, control >0.42 µmol/min/g)

CaseAddInfo: First cousin twice removed of F1P3, Proband