Glycogen storage disease IX
Glycogen structure
Symptoms	Enlarged liver[1]
Causes	Mutations in PHKA1, PHKA2, PHKB, or PHKG2 genes[2]
Diagnostic method	CBC, Urinalysis[1][3]
Treatment	Physical therapy, follow metabolic nutritionist[1]

Glycogen storage disease type IX is a hereditary deficiency of glycogen phosphorylase kinase B that affects the liver and skeletal muscle tissue. It is inherited in an X-linked or autosomal recessive manner.^[1]

Signs and symptoms

The signs and symptoms in glycogen storage disease type IX include:^[1]

• Enlarged liver
• Slowed growth
• Motor development delay (mild)
• Low blood sugar accompanied by ketosis
• Lack of muscle tone

Most of these signs and symptoms diminish as adulthood sets in.^[1]

Genetics

Glycogen storage disease type IX can be inherited via:^[2][4]

• X-linked recessive inheritance due to mutations at either PHKA1 or the PHKA2 (most common^[5]) gene
• Autosomal recessive could be the inheritance pattern for an affected individual when the genes PHKB or PHKG2 have a mutation.

Diagnosis

The diagnosis of glycogen storage disease IX consists of the following:^[1][3]

• Complete blood count
• Urinalysis
• Histological study of the liver (via biopsy)
• Genetic testing
• Physical exam

Types

There are two types of this inherited condition, glycogen storage disease IXa1 and glycogen storage disease IXa2 that affect the liver of an individual.^[6] Mutations in PHKA2 have been seen in individuals with glycogen storage disease IXa2.^{[medical citation needed]}

Management

The management of Glycogen storage disease IX requires treatment of symptoms by frequent intake of complex carbohydrates and protein to combat the low blood sugar. A nutritionist will advise on suitable diets. Liver function is regularly monitored and problems managed as they arise. However, liver problems have only been successfully treated by a transplant. Routine checks of metabolism are needed to ensure blood sugar (glucose) and ketones are managed. Regular moderate exercise is beneficial, although over-vigorous exercise is to be avoided, especially in those with enlarged livers.^[1][7]

See also

• Glycogen storage disease

References

Further reading

• Johnson, Abiodun O.; Goldstein, Jennifer L.; Bali, Deeksha (July 2012). "Glycogen Storage Disease Type IX". Journal of Pediatric Gastroenterology and Nutrition. 55 (1): 90–92. doi:10.1097/MPG.0b013e31823276ea. PMID 21857251.
• Özen, Hasan (14 May 2007). "Glycogen storage diseases: New perspectives". World Journal of Gastroenterology. 13 (18): 2541–2553. doi:10.3748/wjg.v13.i18.2541. ISSN 1007-9327. PMC 4146814. PMID 17552001.
• Albash, Buthainah; Imtiaz, Faiqa; Al-Zaidan, Hamad; Al-Manea, Hadeel; Banemai, Mohammed; Allam, R.; Al-Suheel, Ali; Al-Owain, Mohammed (2014). "Novel PHKG2 mutation causing GSD IX with prominent liver disease: report of three cases and review of literature". European Journal of Pediatrics. 173 (5): 647–653. doi:10.1007/s00431-013-2223-0. ISSN 1432-1076. PMID 24326380. S2CID 37564174.
• Stoler, edited by Raymond R. Tubbs, Mark H.; Stoler, Mark H. (2009). Cell and tissue based molecular pathology (1st ed.). Philadelphia: Churchill Livingstone/Elsevier. ISBN 978-1437719482. Retrieved 6 December 2017. {{cite book}}: |first1= has generic name (help)CS1 maint: multiple names: authors list (link)

External links

Scholia has a topic profile for Glycogen storage disease type IX.

• Media related to Glycogen storage disease type IX at Wikimedia Commons