Synonyms: CDG syndrome type Ia | CDG-Ia | CDG1A | Carbohydrate deficient glycoprotein syndrome type Ia | Congenital disorder of glycosylation type 1a | Congenital disorder of glycosylation type Ia | Phosphomannomutase 2 deficiency
A rare congenital disorder of N-glycosylation and is characterized by cerebellar dysfunction abnormal fat distribution inverted nipples strabismus and hypotonia. 3 forms of PMM2-CDG can be distinguished: the infantile multisystem type late-infantile and childhood ataxia-intellectual disability type (3-10 yrs old) and the adult stable disability type. Infants usually develop ataxia psychomotor delay and extraneurological manifestations including failure to thrive enteropathy hepatic dysfunction coagulation abnormalities and cardiac and renal involvement. The phenotype is however highly variable and ranges from infants who die in the first year of life to mildly involved adults.
Data from Orphanet are used to provide information on a disease's name, synonym(s), and overview. Reference: Access aggregated data from Orphanet at Orphadata. Orphadata: Free access data from Orphanet. © INSERM 1999. Available on http://www.orphadata.org. Data version September 2026
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PMM2-CDG?
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Advocacy Organizations
Access to Life NGO
Access to Life is Ukraine’s first patient advocacy organization for rare genetic epilepsies, anchored in Dravet syndrome and SCN1A-related conditions. We support 600+ families nationwide, advocate for a national clinical protocol and drug access, and are building Ukraine’s National Patient Resource Centre and Patient Registry for genetic epilepsies.
Biliary Atresia and Liver Care Africa
To create awareness, provide support, and advocate for better healthcare services for individuals and families affected by biliary atresia and liver diseases.
CDG CARE
CDG CARE (Community Alliance and Resource Exchange) is a 501(c)(3) nonprofit public charity dedicated to representing all Congenital Disorders of Glycosylation (CDG) — a group of rare, inherited metabolic disorders that disrupt a complex enzymatic process essential to nearly every system in the body. Founded by parents seeking information, connection, and hope, CDG CARE has grown into a global organization serving patients, families, clinicians, and researchers across more than 200 known CDG types. Our mission is to raise awareness, support families, and fund research to improve the diagnosis, care, and treatment of CDGs. We pursue this mission through programs that meet families wherever they are in their journey, from the moment of diagnosis through the search for therapies. At every level of our work, CDG CARE is driven by a simple belief: that no family facing a CDG diagnosis should feel alone, and that together... families, scientists, clinicians, and advocates, we can move research, therapies, and hope forward.
CDG Canada
CDG Canada supports patients and families affected by Congenital Disorders of Glycosylation (CDG).
CDG UK
Supporting families in the UK affected by Congenital Disorders of Glycosylation.
Genetic Epilepsy Team Australia
Collaboration of research and care
Global Liver Institute
To improve the lives of individuals and families impacted by liver disease through promoting innovation, encouraging collaboration, and scaling optimal approaches to help eradicate liver diseases.
Legacy Bridges Foundation, Inc
The Legacy Bridges Foundation, Inc. is a 501(c)3 non-profit organization founded to bridge the gap to support, educate and advocate for individuals, families and caregivers of those living with epilepsy and other seizure related disorders. The Legacy Bridges Foundation, Inc. is dedicated to helping champions live a sustainable life through participation of essential supportive programs and service
Louisiana Metabolic Disorders Coalition
We support, educate, and advocate for patients & families affected by metabolic disorders.
Mississippi Metabolics Foundation
Our mission at Mississippi Metabolics Foundation (MMF) is to advocate, educate, and support families in MS affected by genetic metabolic disorders/inborn errors of metabolism (IEM's). MMF promotes initiatives and further advancements in legislation, education, research, clinical trials, studies, therapies, targeted treatments, and eventual cures for IEM’s and all rare diseases.
Portuguese Association for CDG
The APCDG aims to holistically support families affected by a CDG. Our mission based on the pillars of disease awareness, education, research and to subsequently, speed up the development of therapies that will significantly benefit patients and their family members. We believe that only by adopting a patient-centric approach we will find ways to improve their quality of life.
Rare Epilepsy Network (REN)
REN connects and empowers the rare epilepsy community to collaborate across research, care, education, and advocacy to improve outcomes for patients and families.
ReNU2 Foundation
ReNU2 Foundation supports families affected by RNU2-2-related neurodevelopmental disease. We foster collaboration, raise awareness, and advance research—pursuing a world where every family has testing, informed care, community, and treatment.
Uganda Alliance of Patients Organization
Supporting patients to access quality, safe and patient-centered healthcare services.
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Clinical Trials
For a list of clinical trials in this disease area, please click here.