Ribose-5-phosphate isomerase deficiency: Difference between revisions

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{{Infobox medical condition (new)
 
{{Infobox medical condition
| name            = Ribose-5-phosphate isomerase deficiency
| name            = Ribose-5-phosphate isomerase deficiency
| synonyms        = RPI deficiency<ref>{{cite web |title=OMIM Entry - # 608611 - RIBOSE 5-PHOSPHATE ISOMERASE DEFICIENCY |url=http://omim.org/entry/608611 |website=omim.org |accessdate=16 March 2019}}</ref>
| synonyms        = RPI deficiency
| symptoms        =  
| field          = [[Neurology]], [[Metabolic disorder]]
| complications  =
| symptoms        = [[Leukoencephalopathy]], [[developmental delay]], [[seizures]], [[ataxia]]
| onset          =  
| onset          = [[Infancy]]
| duration        =  
| duration        = [[Chronic]]
| types          =
| causes          = [[Genetic mutation]] in the [[RPIA gene]]
| causes          =  
| risks          = [[Autosomal recessive inheritance]]
| risks          =  
| diagnosis      = [[Genetic testing]], [[MRI]], [[Metabolic screening]]
| diagnosis      =  
| differential    = [[Other leukoencephalopathies]], [[Lysosomal storage disorders]]
| differential    =  
| treatment      = [[Supportive care]], [[Symptomatic treatment]]
| prevention      =
| prognosis      = [[Variable]], often [[progressive]]
| treatment      =  
| frequency      = [[Extremely rare]], only a few cases reported
| medication      =
| prognosis      =  
| frequency      =  
| deaths          =
}}
}}
 
{{Short description|A rare metabolic disorder}}
'''Ribose-5-phosphate isomerase deficiency''' is a human disorder caused by mutations in the [[pentose phosphate pathway]] [[enzyme]] [[ribose-5-phosphate isomerase]]. With only three diagnosed patients over a 27-year period, RPI deficiency is currently the [[Rare disease|rarest disease]] in the world.<ref name="wamelink">{{cite journal |last=Wamelink |first=M. M. |last2=Grüning |first2=N. M. |last3=Jansen |first3=E. E. |last4=Bluemlein |first4=K. |last5=Lehrach |first5=H. |last6=Jakobs |first6=C. |last7=Ralser |first7=M. |title=The difference between rare and exceptionally rare: molecular characterization of ribose 5-phosphate isomerase deficiency |journal=[[Journal of Molecular Medicine|J. Mol. Med.]] |volume=88 |issue=9 |year=2010 |pages=931–39 |doi=10.1007/s00109-010-0634-1 |pmid=20499043 |hdl=1871/34686 }}</ref>
{{Medical condition (new)}}
 
'''Ribose-5-phosphate isomerase deficiency''' is an extremely rare [[metabolic disorder]] characterized by a deficiency in the enzyme [[ribose-5-phosphate isomerase]] (RPI). This enzyme is crucial in the [[pentose phosphate pathway]], which is important for the production of [[nucleotides]] and the management of [[oxidative stress]] in cells.
== Mechanism ==
==Pathophysiology==
In the search for an explanation for this rarity, it has been found that the patient has a seldom-seen [[allelic]] combination.<ref name="wamelink" /> One allele is a non-functional [[null allele]], while the other encodes for a partially active enzyme. Furthermore, the partially functional allele has [[Gene expression|expression]] deficits that depend on the [[cell type]] in which it is expressed. Therefore, some of the patient's cells have a considerable amount of Rpi activity, whereas others do not.
Ribose-5-phosphate isomerase is an enzyme that catalyzes the conversion of [[ribose-5-phosphate]] to [[ribulose-5-phosphate]]. This reaction is part of the non-oxidative phase of the pentose phosphate pathway, which is essential for the synthesis of nucleotides and nucleic acids. A deficiency in this enzyme disrupts the balance of metabolites in the pathway, leading to an accumulation of certain sugars and a deficiency of others, which can affect cellular function and lead to the symptoms observed in this disorder.
 
==Clinical Presentation==
The molecular cause of the pathology is not fully understood. One hypothesis is that [[ribose-5-phosphate]] may lack for [[RNA synthesis]]; another possibility is that the accumulation of <small>D</small>-[[ribitol]] and <small>D</small>-[[arabitol]] may be toxic.
The clinical presentation of ribose-5-phosphate isomerase deficiency can vary, but it often includes neurological symptoms such as [[developmental delay]], [[intellectual disability]], and [[seizures]]. Some patients may also present with [[leukoencephalopathy]], a condition characterized by the degeneration of white matter in the brain. The severity of symptoms can vary widely among affected individuals.
 
==Diagnosis==
==Diagnosis==
Symptoms include [[optic atrophy]], [[nystagmus]], [[cerebellar ataxia]], [[seizures]], [[spasticity]], [[psychomotor retardation]], [[leukoencephalopathy]] and global [[developmental delay]].<ref>{{Cite web|url=http://www.malacards.org/card/ribose_5_phosphate_isomerase_deficiency|title=Ribose 5-Phosphate Isomerase Deficiency disease: Malacards - Research Articles, Drugs, Genes, Clinical Trials|website=www.malacards.org|access-date=2018-03-05}}</ref>
Diagnosis of ribose-5-phosphate isomerase deficiency is challenging due to its rarity and the non-specific nature of its symptoms. It often involves a combination of clinical evaluation, [[magnetic resonance imaging]] (MRI) of the brain, and specialized metabolic testing. Genetic testing can confirm the diagnosis by identifying mutations in the RPIA gene, which encodes the ribose-5-phosphate isomerase enzyme.
 
==Treatment==
==Treatment==
There is no current treatment as well as prognosis for ribose-5-phosphate isomerase deficiency.
Currently, there is no specific treatment for ribose-5-phosphate isomerase deficiency. Management of the condition is primarily supportive and symptomatic. This may include [[anticonvulsant]] medications to control seizures, physical therapy, and educational support to address developmental delays. Research into potential therapies is ongoing, but due to the rarity of the condition, progress is slow.
 
==Prognosis==
== History ==
The prognosis for individuals with ribose-5-phosphate isomerase deficiency varies depending on the severity of the symptoms and the effectiveness of supportive care. Some individuals may have a relatively stable course, while others may experience progressive neurological decline.
In 1999 van der Knaap and colleagues <ref>van der Knapp MS, Wevers RA, Struys EA, et al. Leukoencephalopathy associated with a disturbance in the metabolism of polyols.Ann Neurol. 1999;46(6):925-928.</ref> <ref>Huck, J. H. J.; Verhoeven, N. M.; Struys, E. A.; Salomons, G. S.; Jakobs, C.; Van Der Knaap, M. S. (2004). "Ribose-5-Phosphate Isomerase Deficiency: New Inborn Error in the Pentose Phosphate Pathway Associated with a Slowly Progressive Leukoencephalopathy". The American Journal of Human Genetics 74 (4): 745–751. PMC 1181951. {{PMID|14988808}}. doi:10.1086/383204.</ref> described a 14-year-old boy with developmental delay, insidious psychomotor regression, epilepsy, leukoencephalopathy and abnormal polyol metabolism. Later, Naik and colleagues <ref>Naik N, Shah A, Wamelink MMC, van der Knaap MS, Hingwala
==Epidemiology==
D. Rare case of ribose 5 phosphate isomerase deficiency with slowly progressive leukoencephalopathy. Neurology. 2017;89:1-2.</ref> reported a second case, an 18-year-old man with seizures, psychomotor regression and diffuse white matter abnormality. A third case was reported in 2018 by Sklower Brooks and colleagues, a child with neonatal onset leukoencephalopathy and psychomotor delays.<ref>Sklower Brooks S, Anderson S, Bhise V,  Botti  C. Further Delineation of Ribose-5-phosphate Isomerase Deficiency: Report of a Third Case, Journal of Child Neurology: First Published August 10, 2018 Journal of Child Neurology. https://doi.org/10.1177/0883073818789316 </ref>
Ribose-5-phosphate isomerase deficiency is one of the rarest metabolic disorders, with only a few cases reported in the medical literature. Its exact prevalence is unknown, but it is considered to be extremely rare.
 
==Related pages==
== References ==
* [[Pentose phosphate pathway]]
{{Reflist}}
* [[Metabolic disorder]]
== External links ==
* [[Leukoencephalopathy]]
{{Medical resources
* [[Intellectual disability]]
| OMIM = 608611
[[Category:Metabolic disorders]]
| Orphanet= 440706
}}
[[Category:Rare diseases]]
[[Category:Rare diseases]]
{{dictionary-stub1}}

Latest revision as of 04:43, 4 April 2025


Ribose-5-phosphate isomerase deficiency
Synonyms RPI deficiency
Pronounce N/A
Specialty N/A
Symptoms Leukoencephalopathy, developmental delay, seizures, ataxia
Complications N/A
Onset Infancy
Duration Chronic
Types N/A
Causes Genetic mutation in the RPIA gene
Risks Autosomal recessive inheritance
Diagnosis Genetic testing, MRI, Metabolic screening
Differential diagnosis Other leukoencephalopathies, Lysosomal storage disorders
Prevention N/A
Treatment Supportive care, Symptomatic treatment
Medication N/A
Prognosis Variable, often progressive
Frequency Extremely rare, only a few cases reported
Deaths N/A


A rare metabolic disorder


Template:Medical condition (new) Ribose-5-phosphate isomerase deficiency is an extremely rare metabolic disorder characterized by a deficiency in the enzyme ribose-5-phosphate isomerase (RPI). This enzyme is crucial in the pentose phosphate pathway, which is important for the production of nucleotides and the management of oxidative stress in cells.

Pathophysiology[edit]

Ribose-5-phosphate isomerase is an enzyme that catalyzes the conversion of ribose-5-phosphate to ribulose-5-phosphate. This reaction is part of the non-oxidative phase of the pentose phosphate pathway, which is essential for the synthesis of nucleotides and nucleic acids. A deficiency in this enzyme disrupts the balance of metabolites in the pathway, leading to an accumulation of certain sugars and a deficiency of others, which can affect cellular function and lead to the symptoms observed in this disorder.

Clinical Presentation[edit]

The clinical presentation of ribose-5-phosphate isomerase deficiency can vary, but it often includes neurological symptoms such as developmental delay, intellectual disability, and seizures. Some patients may also present with leukoencephalopathy, a condition characterized by the degeneration of white matter in the brain. The severity of symptoms can vary widely among affected individuals.

Diagnosis[edit]

Diagnosis of ribose-5-phosphate isomerase deficiency is challenging due to its rarity and the non-specific nature of its symptoms. It often involves a combination of clinical evaluation, magnetic resonance imaging (MRI) of the brain, and specialized metabolic testing. Genetic testing can confirm the diagnosis by identifying mutations in the RPIA gene, which encodes the ribose-5-phosphate isomerase enzyme.

Treatment[edit]

Currently, there is no specific treatment for ribose-5-phosphate isomerase deficiency. Management of the condition is primarily supportive and symptomatic. This may include anticonvulsant medications to control seizures, physical therapy, and educational support to address developmental delays. Research into potential therapies is ongoing, but due to the rarity of the condition, progress is slow.

Prognosis[edit]

The prognosis for individuals with ribose-5-phosphate isomerase deficiency varies depending on the severity of the symptoms and the effectiveness of supportive care. Some individuals may have a relatively stable course, while others may experience progressive neurological decline.

Epidemiology[edit]

Ribose-5-phosphate isomerase deficiency is one of the rarest metabolic disorders, with only a few cases reported in the medical literature. Its exact prevalence is unknown, but it is considered to be extremely rare.

Related pages[edit]