|
The glycogen storage diseases are a group of
autosomal recessive disorders resulting from defects in the
synthesis or catabolism of glycogen. |
Glycogen storage
diseases are inherited metabolic disorders of glycogen metabolism.
Different hormones, including insulin, glucagon, and cortisol regulate
the relationship of glycolysis, gluconeogenesis and glycogen synthesis.
The overall
Glycogen
Storage Diseases
incidence is estimated 1 case per 20000-43000 live births.
There are over 12
types and they are classified based on the enzyme deficiency and the
affected tissue.
Disorders of
glycogen degradation may affect primarily the liver, the muscle, or
both.
Type Ia involves
the liver, kidney and intestine (and Ib also leukocytes), and the
clinical manifestations are hepatomegaly, failure to thrive,
hypoglycemia, hyperlactatemia, hyperuricemia and hyperlipidemia.
Type IIIa involves
both the liver and muscle, and IIIb solely the liver. The liver symptoms
generally improve with age.
Type IV usually
presents in the first year of life, with hepatomegaly and growth
retardation. The disease in general is progressive to cirrhosis.
Type VI and
IX are a heterogeneous group of diseases caused by a deficiency of the
liver phosphorylase and phosphorylase kinase system. There is no
hyperuricemia or hyperlactatemia.
Type XI is
characterized by hepatic glycogenosis and renal Fanconi syndrome.
Type II is a
prototype of inborn lysosomal storage diseases and involves many organs
but primarily the muscle.
Types V and VII
involve only the muscle.
Glycogen storage diseases: new
perspectives.
World J
Gastroenterol. 2007 May 14;13(18):2541-53.
|
Differential diagnosis of glycogenoses.Arkh
Patol.1980;42(12):61-71.
Different types
of hepatic, muscular, and generalized forms of glycogen stogare
disease, a hereditary disease caused by glycogen metabolism
disorders, are analysed. The clinical and biochemical features of
these diseases are described. The data on enzyme defects and methods
for their detection in different types of glycogenoses as well as on
the prevalence of the disease in different countries are presented. |
On the basis of specific enzyme deficiencies and
resultant clinical pictures, glycogen storage diseases have been divided
into
three major groups.
-
Hepatic forms:
|
Natural history of hepatic glycogen storage diseases.Presse
Med. 2008 Jul-Aug;37(7-8):1172-7.
Hepatic
glycogen storage diseases are rare inherited conditions affecting
glycogen metabolism. During the last twenty years, medical progress
has allowed children who used to die before they reached the age of
ten years to reach adulthood. It is important to know the natural
history and long-term outcome of these patients to improve their
treatment during childhood. To reach this goal, collaboration
between pediatric specialists and those who treat adults is
essential.
Glycogen storage disease type I--between chronic ambulatory
follow-up and pediatric emergency.
J Gastrointestin Liver Dis.
2007 Mar;16(1):47-51.
BACKGROUND AND
AIMS: To describe the characteristics of patients with type I
glycogenosis, the presentation types, the main clinical signs, the
diagnostic criteria and also the disease outcomes on long term
follow-up. METHODS: The study group consisted of 6 patients (medium
age 3 years 6 months) admitted in hospital between 2001 and 2005 and
followed-up for 1 to 5 years. The sex ratio was 1:1. RESULTS: The
referral reasons varied from hepatomegaly incidentally discovered (3
of 6 patients) to abdominal pain (4 of 6 patients), growth failure
(3 of 6 patients), symptoms of hypoglycemia (3 of 6 patients),
recurrent epistaxis (1 patient). Hepatomegaly was present in all
cases. Biological profile: hypoglycemia, increased transaminase
values, hypertriglyceridemia, lactic acidosis, normal uric acid
levels. Two patients had neutropenia and other two had increased
glomerular filtration rate. Liver biopsy showed glycogen-laden
hepatocytes and markedly increased fat. Four patients had type Ia
and 2 patients type Ib glycogenosis. The therapy consisted of: diet,
ursodeoxycholic acid, granulocyte colony-stimulating factor, broad
spectrum antibiotics for those with type Ib glycogenosis. The
follow-up parameters were clinical, biological, imaging. Metabolic
interventions and antiinfectious therapy were necessary. All
patients are alive, two of them on the waiting list for liver
transplantation. CONCLUSIONS: Glycogen storage disease type I is a
rare condition, but with possible life-threatening consequences. It
has to be kept in mind whenever important hepatomegaly and/or
hypoglycemia are present.
Hepatocyte
transplantation for glycogen storage disease type Ib.
Cell Transplant.
2007;16(6):629-37.
Glycogen
storage disease type I (GSD-I) is a group of autosomal recessive
disorders with an incidence of 1 in 100,000. The two major subtypes
are GSD-Ia, caused by a deficiency of glucose-6-phosphatase
(G6Pase), and GSD-Ib, caused by a deficiency of glucose-6-phosphate
transporter (G6PT). We report that a substantial improvement was
achieved following several infusions of hepatocytes in a patient
with GSD-Ib. Hepatocytes were isolated from the unused cadaveric
whole livers of two donors. At the first transplantation,
approximately 2 x 10(9) cells (2% of the estimated recipient's total
hepatocytes) were infused. Seven days later 1 x 10(9) (1% of liver
mass) cryopreserved hepatocytes from the same donor were infused,
and an additional 3 x 10(9) (3% of liver mass) cells from the second
donor were infused 1 month after the second transplantation. After
the hepatocyte transplantation, the patient showed no hypoglycemic
symptoms despite the discontinuation of cornstarch meals. Liver
biopsies on posttransplantation days 20 and 250 showed a normal
level of glucose-6-phosphatase activity in presolubilization assay
that was very low before transplantation. This was the first and
successful clinical hepatocyte transplantation in Korea. In this
study, hepatocyte transplantation allowed a normal diet in a patient
with GSD-Ib, with substantial improvement in their quality of life.
Hepatocyte transplantation might be an alternative to liver
transplantation and dietary therapy in GSD-Ib.
Patterns of growth in the hepatic glycogenoses.Arch
Dis Child. 1984 Jul;59(7):657-60.
Longitudinal
growth data from 31 patients with hepatic glycogen storage disease
(type I (8 patients), type Ib (three patients), type III (13
patients), and type IX (phosphorylase kinase deficiency) (7
patients) ) have been reviewed. All patients were below the mean for
height at presentation; the mean height standard deviation scores
were -2.13 (type I), -2.0 (type Ib), -2.4 (type III), and -1.6 (type
IX). Untreated, most patients with type I and Ib grew slowly with no
catch up growth but three patients with mild disease grew normally.
Most children with type III disease grew at a normal velocity
throughout childhood. Puberty was delayed and final height normal.
Some of the children with type III and all of those with type IX had
catch up growth throughout childhood. Intensive treatment of
patients with severe forms of type I and Ib disease resulted in
catch up growth, but this was not complete if the treatment was
started late. |
Example:
von Gierke disease (type I glycogenosis). This results from deficiency
of the hepatic enzyme glusose-6-phosphatase, which is essential for the
conversion of glucose-6-phosphate to glucose.
The major effects of this enzyme
deficiency are:
-
Accumulation of glycogen because it
cannot be broken down to free glucose ; Low blood glucose
(hypoglycemia).
|
Nutrition therapy for hepatic glycogen storage
diseases.
J Am
Diet Assoc. 1993 Dec;93(12):1423-30.
Hepatic
glycogen storage diseases (GSD) are a group of rare genetic
disorders in which glycogen cannot be metabolized to glucose in the
liver because of one of a number of possible enzyme deficiencies
along the glycogenolytic pathway. Patients with GSD are usually
diagnosed in infancy or early childhood with hypoglycemia,
hepatomegaly, poor physical growth, and a deranged biochemical
profile. Dietary therapies have been devised to use the available
alternative metabolic pathways to compensate for disturbed
glycogenolysis in GSD I (glucose-6-phosphatase deficiency), GSD III
(debrancher enzyme deficiency), GSD VI (phosphorylase deficiency,
which is less common), GSD IX (phosphorylase kinase deficiency), and
GSD IV (brancher enzyme deficiency). In GSD I, glucose-6-phosphate
cannot be dephosphorylated to free glucose. Managing this condition
entails overnight continuous gastric high-carbohydrate feedings;
frequent daytime feedings with energy distributed as 65%
carbohydrate, 10% to 15% protein, and 25% fat; and supplements of
uncooked cornstarch. In GSD III, though glycogenolysis is impeded,
gluconeogenesis is enhanced to help maintain endogenous glucose
production. In contrast to treatment for GSD I, advocated treatment
for GSD III comprises frequent high-protein feedings during the day
and a high-protein snack at night; energy is distributed as 45%
carbohydrate, 25% protein, and 30% fat. Patients with GSD IV, VI,
and IX have benefited from high-protein diets similar to that
recommended for patients with GSD III. |
Contents

|