Glycogen storage disease type II
Channel: all the knowledge of the universe PRINCIPIA
Date: 2022-01-20

Glycogen storage disease type II, by Wikipedia https://en.wikipedia.org/wiki?curid=1010229 / CC BY SA 3.0

#Autosomal_recessive_disorders
#Hepatology
#Inborn_errors_of_carbohydrate_metabolism
#Lysosomal_storage_diseases
#Rare_diseases
Glycogen storage disease type II, also called Pompe disease, is an autosomal recessive metabolic disorder which damages muscle and nerve cells throughout the body.
It is caused by an accumulation of glycogen in the lysosome due to deficiency of the lysosomal acid alpha-glucosidase enzyme.
It is the only glycogen storage disease with a defect in lysosomal metabolism, and the first glycogen storage disease to be identified, in 1932 by the Dutch pathologist J. C. Pompe.
The build-up of glycogen causes progressive muscle weakness （myopathy） throughout the body and affects various body tissues, particularly in the heart, skeletal muscles, liver and the nervous system.
The infantile form usually comes to medical attention within the first few months of life.
The usual presenting features are cardiomegaly （92%）, hypotonia （88%）, cardiomyopathy （88%）, respiratory distress （78%）, muscle weakness （63%）, feeding difficulties （57%） and failure to thrive （50%）.
The main clinical findings include floppy baby appearance, delayed motor milestones and feeding difficulties.
Moderate hepatomegaly may or may not be present.
Facial features include macroglossia, wide open mouth, wide open eyes, nasal flaring （due to respiratory distress）, and poor facial muscle tone.
Cardiopulmonary involvement is manifested by increased respiratory rate, use of accessory muscles for respiration, recurrent chest infections, decreased air entry in the left lower zone （due to cardiomegaly）, arrhythmias and evidence of heart failure.
Prior to the development of a treatment, median age at death in untreated cases was 8.
7 months, usually due to cardiorespiratory failure, however this outcome is drastically changed since treatment has been available, improving with early access...