Dolichol-phosphate-mannose synthase 1 deficiency is a very rare inherited disease. Doctors also call it DPM1-CDG. It belongs to a group called congenital disorders of glycosylation, or CDG. In this disease, the body cannot add some sugar chains to proteins and fats in the right way. These sugar chains are important because they help many body parts work well, especially the brain, muscles, eyes, liver, and blood clotting system. [1]
Dolichol-phosphate-mannose synthase 1 deficiency, usually called DPM1 deficiency or DPM1-CDG, is an ultra-rare congenital disorder of glycosylation. It happens because the DPM1 gene does not work normally, so the body cannot make an important sugar donor used for several glycosylation pathways. Because glycosylation helps proteins fold, travel, and work correctly, this disorder can affect the brain, muscles, feeding, vision, liver tests, clotting, growth, and development. In reported patients, common problems include early seizures, low muscle tone, developmental delay, small head size, eye problems, and multisystem illness. [1][2][3]
This problem happens because the DPM1 gene does not work normally. The DPM1 protein is part of an enzyme that makes dolichol-phosphate-mannose, a small but very important building block used in several glycosylation pathways. When this step is weak or missing, many proteins are made in an incomplete form, so the body cannot grow and function in the usual way. [2]
Most affected children become sick in infancy or early childhood, but severity can differ. Some children have very severe disease with seizures and major developmental delay. Others can have a milder form with walking problems, ataxia, or eye findings. Because it is rare, diagnosis is often delayed unless doctors think about CDG early. [3]
Other names
Other names used for this condition include DPM1-CDG, congenital disorder of glycosylation due to DPM1 deficiency, congenital disorder of glycosylation type Ie, and CDG-Ie. Older papers often used CDG-Ie, while newer sources often use DPM1-CDG because the name points directly to the changed gene. [4]
Types
There are no widely accepted disease “types” inside DPM1 deficiency like type 1, type 2, and type 3. Instead, doctors usually describe it by severity or by the main body system affected. So the simple list below is a clinical way to understand the different patterns seen in patients, not a formal official subtype system. [5]
- Severe infantile form means symptoms start very early, often with poor muscle tone, feeding trouble, seizures, and major developmental problems. [6]
- Neurologic-predominant form means brain and nerve symptoms are the main problems, such as delay, ataxia, neuropathy, and seizures. [7]
- Muscle-predominant form means weakness, high creatine kinase, and dystroglycanopathy-like muscle disease are more obvious. [8]
- Eye-predominant form means visual or eye movement problems such as strabismus, nystagmus, or retinal disease are important signs. [9]
- Gastrointestinal-predominant form means severe feeding and gut problems are especially marked in some patients. [10]
Causes
This disease does not have 20 separate common causes like an infection or injury. The main proven cause is harmful changes in both copies of the DPM1 gene. To match your requested format, the 20 points below explain the cause in a simple, step-by-step way. [11]
- The direct cause is a pathogenic variant in the DPM1 gene. A pathogenic variant means a DNA change that harms the gene’s job. [12]
- The disease usually needs two changed copies of DPM1, one from each parent. This is called autosomal recessive inheritance. [13]
- A child becomes affected when the two changed copies together lower DPM1 enzyme function too much. [14]
- Parents are often carriers. A carrier usually has one working copy and one changed copy, so the parent is often healthy. [15]
- Some variants are missense variants. This means one DNA letter change makes one wrong amino acid in the protein. [16]
- Some variants can affect the start codon, so the protein may not start being made in the normal way. [17]
- Some variants can be small deletions. This means a few DNA letters are missing, which can change the protein shape. [18]
- Some variants are splice variants. These can make the cell cut the RNA in the wrong place and build an abnormal protein. [19]
- The DPM1 protein is the catalytic subunit, which means it does the main chemical work in the enzyme complex. [20]
- When DPM1 is weak, the body makes too little dolichol-phosphate-mannose. This molecule is needed for normal glycosylation. [21]
- Low dolichol-phosphate-mannose harms N-glycosylation, one major sugar-adding pathway. [22]
- It also harms O-mannosylation, which is important for some muscle and brain proteins. [23]
- It can also affect GPI-anchor formation, another pathway that helps proteins sit correctly on cell surfaces. [24]
- Because many proteins need glycosylation, the disorder becomes a multisystem disease and can affect many organs at once. [25]
- The brain is often strongly affected because nerve cells depend on well-made proteins for growth and signaling. [26]
- Muscles can be affected because faulty glycosylation can lower normal alpha-dystroglycan function. [27]
- Eye disease can happen because retinal and eye movement pathways also depend on normal glycoproteins. [28]
- Blood clotting problems can happen because clotting factors are glycoproteins too. [29]
- Different variants can leave different amounts of enzyme activity, which helps explain why some patients are milder and some are more severe. [30]
- So, in very simple words, the full cause is: a child inherits two harmful DPM1 gene changes, the body cannot make enough dolichol-phosphate-mannose, and many proteins are built with the wrong sugar chains. [31]
Symptoms
- Developmental delay means the child learns skills more slowly than expected, such as sitting, standing, talking, or understanding. This is one of the most common signs. [32]
- Motor delay means movement skills are late. The child may take much longer to roll, sit, crawl, stand, or walk. [33]
- Hypotonia means low muscle tone. The baby may feel floppy and may have weak head control. [34]
- Seizures are sudden abnormal brain electrical events. They may cause staring, jerking, stiffness, or loss of awareness. [35]
- Microcephaly means the head is smaller than expected for age and sex. This can be present at birth or appear later. [36]
- Ataxia means poor balance and unsteady movement. The child may walk with a wide base or fall often. [37]
- Peripheral neuropathy means the nerves outside the brain and spinal cord do not work well. This can cause weakness, reduced reflexes, or sensory problems. [38]
- Eye abnormalities are common. These can include retinal disease, visual problems, or poor eye alignment. [39]
- Nystagmus means the eyes make repeated uncontrolled movements. This can reduce clear vision. [40]
- Strabismus means the eyes do not point in the same direction. One eye may turn in, out, up, or down. [41]
- Feeding difficulty means trouble sucking, swallowing, or taking enough food. Babies may need special feeding support. [42]
- Poor growth or failure to thrive means the child does not gain weight and length as expected. [43]
- Muscle weakness may appear when the muscle form of the disease is important. The child may move very little or tire easily. [44]
- High bleeding tendency can occur when blood clotting proteins are affected. A child may bruise easily or bleed longer than usual. [45]
- Liver test abnormalities may occur even when liver symptoms are not obvious. Blood tests can show raised enzymes. [46]
Diagnostic tests
Doctors diagnose DPM1 deficiency by putting together the history, physical examination, biochemical tests, and genetic testing. No single bedside sign can confirm it alone. The strongest proof usually comes from abnormal glycosylation testing plus a disease-causing DPM1 result on genetic testing. [47]
- Physical exam: growth check. The doctor measures weight, length, and head size. This helps find poor growth and microcephaly. [48]
- Physical exam: neurologic exam. The doctor checks alertness, tone, reflexes, coordination, and developmental level. This can show hypotonia, delay, ataxia, or neuropathy. [49]
- Physical exam: eye exam. The doctor looks for strabismus, nystagmus, poor fixation, or other visual problems. [50]
- Manual test: developmental assessment. This is a structured check of motor, language, and social milestones. It shows which skills are delayed. [51]
- Manual test: muscle tone assessment. The doctor gently moves the arms, legs, neck, and trunk to feel if the body is floppy or stiff. [52]
- Manual test: gait and balance testing. If the child can stand or walk, the doctor watches posture, steadiness, and coordination for signs of ataxia. [53]
- Lab test: serum transferrin isoelectric focusing. This is a key screening test for many N-glycosylation disorders. It looks for an abnormal transferrin pattern that suggests CDG. [54]
- Lab test: transferrin mass spectrometry. This is another way to study transferrin glycosylation and can support or refine the biochemical diagnosis. [55]
- Lab test: alpha-dystroglycan analysis. This helps when muscle involvement is present, because DPM1 defects can reduce normal glycosylation of alpha-dystroglycan. [56]
- Lab test: creatine kinase, or CK. High CK can point to muscle damage or muscular dystrophy-like disease. [57]
- Lab test: liver enzymes. Tests such as AST and ALT can be raised and may show liver involvement. [58]
- Lab test: coagulation profile. Clotting studies can look for problems in clotting factors, which may explain bruising or bleeding. [59]
- Lab test: plasma or serum glycan studies. These tests look more broadly at sugar-chain abnormalities and can support the diagnosis of a CDG. [60]
- Pathological or functional test: enzyme studies in fibroblasts. In some research or specialized settings, doctors study patient cells to show low Dol-P-Man synthase activity or related glycosylation defects. [61]
- Genetic test: single-gene DPM1 testing. This looks directly for pathogenic variants in the DPM1 gene. [62]
- Genetic test: exome or genome sequencing. This is useful when the disease is not clear at first or when doctors are testing many rare genetic conditions at once. [63]
- Electrodiagnostic test: EEG. EEG records brain electrical activity and helps evaluate seizures. [64]
- Electrodiagnostic test: nerve conduction study. This checks how fast and how well peripheral nerves carry signals, which can help find neuropathy. [65]
- Imaging test: brain MRI. MRI can show brain structure changes that support a neurologic disorder, though findings are not always specific only to DPM1 deficiency. [66]
- Imaging test: muscle MRI or other targeted imaging when needed. In patients with strong muscle symptoms, imaging can help show muscle involvement and guide further testing. [67]
Non-pharmacological treatments
- Neurology-led seizure plan. A written seizure action plan helps families know what to do during fever, breakthrough seizures, clusters, or prolonged seizures. It improves speed of response and lowers the chance of delayed rescue treatment. In DPM1-CDG, seizures can start very early, so practical home planning matters a lot. [1][6]
- Regular EEG and clinical seizure review. EEG does not cure the disease, but it helps the team understand seizure type, treatment response, and urgency. This matters because different seizure patterns may need different anti-seizure medicines and monitoring intensity. [6][7]
- Physical therapy. Physical therapy supports posture, joint range, head control, balance, and prevention of contractures. In low muscle tone or motor delay, repeated guided movement helps the nervous system practice safer and more efficient movement patterns. [4][6]
- Occupational therapy. Occupational therapy helps hand use, positioning, daily skills, adaptive seating, splint planning, and sensory support. It aims to improve function, comfort, and caregiver handling. [4][5]
- Speech and feeding therapy. Many CDG patients have oral-motor weakness, swallow difficulty, or poor coordination. Feeding therapy improves safer swallowing, texture choice, pacing, and aspiration prevention. It also supports communication development. [4][5]
- Nutrition review with growth tracking. A dietitian can help with calories, protein, hydration, constipation prevention, and safe textures. The purpose is to prevent undernutrition and reduce stress from long feeds or vomiting. [4][5]
- High-calorie feeding strategies when needed. Small frequent feeds, calorie concentration, and individualized texture changes can improve weight gain when oral intake is poor. This supports growth without forcing unsafe large-volume feeds. [4][5]
- Tube feeding when oral feeding is unsafe or inadequate. Nasogastric or gastrostomy feeding may be needed if there is recurrent aspiration, severe fatigue with feeding, or failure to thrive. This can improve nutrition and lower lung risk. [4][5]
- Aspiration prevention positioning. Upright feeding, careful pacing, and post-feed positioning can lower reflux and aspiration risk. This is especially helpful in children with hypotonia or poor swallow coordination. [4][5]
- Vision care and low-vision support. DPM1-CDG may include eye and visual problems. Early eye assessment helps detect refractive errors, strabismus, cortical visual issues, or other complications, so supportive tools can be started early. [1][3]
- Hearing assessment if development is delayed. Hearing problems can worsen speech delay and social development. Early testing makes rehabilitation more effective. [4][5]
- Orthopedic monitoring. Weakness, abnormal tone, or poor mobility can lead to hip, spine, or contracture problems over time. Early bracing, stretching, and seating adjustment can reduce later deformity. [4][6]
- Respiratory care. Chest physiotherapy, suction support when needed, vaccination, and early treatment of respiratory infections can reduce hospitalization risk in children with weak cough or aspiration. [4][5]
- Coagulation and bleeding surveillance. Some CDG patients develop clotting factor abnormalities. Checking coagulation labs before procedures or if there is unusual bruising helps prevent dangerous bleeding or thrombosis. [3][4]
- Liver and muscle enzyme monitoring. Elevated transaminases and creatine kinase have been reported in DPM1-CDG. Periodic blood tests help detect organ stress and guide supportive care. [1][6]
- Developmental early-intervention services. Early intervention programs can improve long-term function by combining therapy, caregiver teaching, and adaptive planning during the most important years of brain development. [4][5]
- Sleep support. Good sleep routines, seizure control, reflux control, and safe positioning can improve irritability, development, and caregiver burnout. Sleep problems often worsen neurological symptoms. [4][6]
- Palliative and complex-care support for severe disease. In very severe infantile disease, comfort-focused support can help with symptoms, decision-making, and family support. This is part of good medical care, not “giving up.” [7][8]
- Genetic counseling. DPM1 deficiency is inherited, so families may benefit from counseling about recurrence risk, testing of relatives, and future pregnancy planning. [3][4]
- Multidisciplinary follow-up. Best care usually includes neurology, genetics, nutrition, gastroenterology, ophthalmology, rehabilitation, and primary care. Because DPM1-CDG affects many organs, team-based care is the safest model. [4][5]
Drug treatments
These medicines are not cures for DPM1 deficiency. They are used only for symptom control, based on the person’s seizure type, feeding problems, reflux, spasticity, drooling, constipation, or other complications. Choice and dose must be set by a clinician. [4][5]
- Levetiracetam (KEPPRA). FDA-labeled for several seizure indications. It is often chosen because it is available as oral and IV forms and is widely used in epilepsy care. Common adverse effects include sleepiness, weakness, dizziness, and behavior changes. [9]
- Diazepam rectal gel (DIASTAT). FDA-labeled for intermittent treatment of bouts of increased seizure activity in selected patients with epilepsy. It is commonly used as a home rescue medicine for prolonged seizures or clusters. Sedation and breathing suppression are key risks. [10]
- Midazolam nasal spray (NAYZILAM). FDA-labeled for acute treatment of intermittent, stereotypic seizure episodes in patients 12 years and older. It may be used when a fast non-rectal rescue option is appropriate. Drowsiness and respiratory depression are important cautions. [11]
- Clobazam (ONFI). FDA-labeled for seizures associated with Lennox-Gastaut syndrome, but sometimes used by epilepsy specialists for difficult seizure control. Main risks are sedation, dependence, and withdrawal. [12]
- Clonazepam (KLONOPIN). FDA-labeled for certain seizure disorders and panic disorder. It may help some seizure types, but sleepiness, tolerance, and dependence can limit long-term use. [13]
- Valproic acid (DEPAKENE/DEPACON). FDA-labeled for several seizure uses. It can be effective in some epilepsies, but liver toxicity, pancreatitis, thrombocytopenia, and pregnancy risks are major concerns, so it must be chosen carefully in medically fragile patients. [14][15]
- Topiramate (TOPAMAX). FDA-labeled as an antiseizure medicine. It can be considered for seizure control, but side effects may include sleepiness, appetite loss, metabolic acidosis, and kidney stone risk. [16]
- Lacosamide (VIMPAT). FDA-labeled for focal seizures and available as oral solution. It may be used when seizure type fits and specialist judgment supports it. Dizziness, nausea, and PR-interval effects are important cautions. [17]
- Gabapentin (NEURONTIN). FDA-labeled for focal seizures as adjunctive therapy and also for neuropathic pain in adults. In selected cases it may help seizures or discomfort, though it is not a DPM1-specific treatment. [18]
- Phenobarbital. FDA labeling describes it as an antiepileptic, and it is still used in some severe or neonatal seizure settings. The major problems are sedation, breathing suppression, and interaction burden. [19]
- Cannabidiol oral solution (EPIDIOLEX). FDA-approved for seizures in Lennox-Gastaut syndrome, Dravet syndrome, and tuberous sclerosis complex, not for DPM1-CDG itself. In selected refractory epilepsy cases, specialists may consider it only when clinically justified. Liver monitoring is important. [20]
- Baclofen (oral). FDA-labeled for spasticity relief. It may help stiffness, painful spasms, and easier caregiving in patients who later develop increased tone. Drowsiness and weakness are common concerns. [21]
- Intrathecal baclofen. FDA-labeled for severe spasticity through pump delivery in selected patients. This is not first-line care, but can help severe tone problems that do not respond to oral treatment. [22]
- Glycopyrrolate oral solution. FDA-approved to reduce severe drooling in children with neurologic conditions. It can be useful when saliva control is poor and aspiration risk is increased, but it may worsen constipation and thicken secretions. [23]
- Omeprazole oral suspension (PRILOSEC). FDA-labeled for acid-related disorders. It may help reflux, esophagitis, or feeding discomfort in patients with GERD symptoms, but it does not treat the genetic disease itself. [24]
- Famotidine oral suspension. FDA-labeled for acid suppression in several GI conditions. It may be used for reflux-related pain or esophagitis when clinically appropriate. [25]
- Ondansetron oral solution (ZOFRAN). FDA-labeled mainly for nausea and vomiting related to chemotherapy, radiation, or surgery, but sometimes used short-term for severe vomiting when a clinician feels benefits outweigh risks. Constipation and QT effects matter. [26]
- Metoclopramide. FDA-labeled for short-term reflux and diabetic gastroparesis in adults. It may sometimes be considered for severe motility problems, but tardive dyskinesia risk means it should be used very carefully and usually briefly. [27]
- Polyethylene glycol 3350. Commonly used for constipation support. It does not treat DPM1 deficiency, but it may help bowel regularity when low tone, immobility, or diet contribute to hard stool. [28]
- Pain or fever medicines as supportive care. Symptom relief during intercurrent illness can lower stress, dehydration risk, and seizure triggering. These are supportive only and should be chosen by age, weight, liver status, and clinician advice. [4][5]
Dietary supplements
There is no supplement proven to correct DPM1 deficiency. Supplements are used only to support nutrition if a clinician finds a deficiency or poor intake. The original DPM1 paper found mannose was not a proven therapy for this subtype. [1][4]
- Vitamin D for low levels or low bone loading.
- Calcium when intake is poor or bone support is needed.
- Iron only if iron deficiency is confirmed.
- Folate only if low or intake is inadequate.
- Vitamin B12 if deficiency is present.
- Zinc if poor growth or deficiency is documented.
- Selenium only when deficiency is proven.
- Multivitamin/mineral for incomplete intake.
- Protein supplements or modular protein if oral intake is too low.
- Omega-3 fatty acids may be used as general nutrition support, but there is no DPM1-specific proof. [4][5][29]
Immunity, regenerative, or stem-cell drug options
At present, there are no FDA-approved immune-booster drugs, regenerative drugs, or stem-cell drugs proven to treat DPM1 deficiency itself. That is the honest evidence-based answer. Reviews of CDG therapy describe this field as mostly supportive care, with experimental future directions still under study. [4][30]
The six research-direction categories people may read about are: gene therapy, mRNA therapy, enzyme or substrate replacement concepts, pharmacologic chaperones, cell-based therapy, and precision metabolic therapy. These are research ideas, not established DPM1 treatments, and they should not be presented as routine care. [30][31]
Surgeries or procedures
- Gastrostomy tube placement for long-term nutrition if swallowing is unsafe or weight gain is poor. [4][5]
- Fundoplication may be considered when severe reflux causes aspiration, pain, or poor growth despite medical treatment. [4][5]
- Tracheostomy may rarely be needed in severe airway or chronic respiratory failure situations. [4][5]
- Orthopedic procedures such as tendon release or hip/spine procedures may be needed later for contractures or deformity from chronic neuromotor problems. [4][6]
- Intrathecal baclofen pump implantation is a procedure option for severe refractory spasticity in carefully selected patients. [22]
Prevention points
Because DPM1 deficiency is genetic, it cannot usually be “prevented” after conception, but complications can be reduced. Use vaccines on time, treat fever and infections early, follow the seizure rescue plan, protect nutrition and hydration, watch swallowing safety, keep therapy appointments, monitor liver and clotting tests, avoid abrupt stopping of anti-seizure medicines, ask before using new supplements, and get genetic counseling for future pregnancies. [4][5][10]
When to see doctors urgently
Get urgent medical help for a first seizure, a seizure lasting more than a few minutes, repeated seizure clusters, blue lips, hard breathing, poor feeding, dehydration, choking, suspected aspiration, unusual bleeding, severe sleepiness, repeated vomiting, or sudden loss of skills. In medically fragile infants, even fever or reduced intake can become serious quickly. [7][8][10]
What to eat and what to avoid
Helpful choices often include soft safe textures, enough calories, enough protein, adequate fluids, fiber as tolerated, small frequent meals, reflux-friendly meal timing, and individualized dietitian plans. For children with swallow difficulty, texture and feeding pace are often more important than any special “miracle food.” [4][5]
Foods or patterns to avoid may include unsafe thin liquids if aspiration risk exists, very large meals, foods that clearly worsen reflux, long fasting, dehydration, unproven megadose supplements, and mannose used as if it were proven for DPM1 deficiency. The early DPM1 study did not support mannose as a therapeutic correction for this subtype. [1][24]
FAQs
1. Is DPM1 deficiency curable? No proven cure exists yet. Care is supportive. [4][30]
2. Is there an FDA-approved DPM1 medicine? No disease-specific FDA-approved medicine was found. [4][5]
3. Is mannose helpful? Not proven for DPM1; the original study found no correction in DPM1-deficient cells. [1]
4. Why are seizures common? The brain is highly sensitive to glycosylation defects. [6][7]
5. Can feeding tubes help? Yes, when weight gain or swallowing safety is poor. [4][5]
6. Can eyesight be affected? Yes, eye and visual problems have been reported. [1][3]
7. Is this disorder inherited? Yes, it is genetic and families may benefit from counseling. [3][4]
8. Is every patient the same? No. Severity varies widely. [3][7]
9. Are supplements enough? No. They can support nutrition but do not fix the gene defect. [4][29]
10. Can surgery ever be needed? Yes, mainly for feeding, reflux, airway, tone, or orthopedic complications. [4][22]
11. What specialist is most important? Usually genetics and neurology, plus nutrition and rehabilitation. [4][5]
12. Can infections be dangerous? Yes, especially in infants with severe disease or aspiration risk. [7][8]
13. Should all anti-seizure drugs be used? No. Drug choice depends on seizure type, age, organ status, and side effects. [9][14]
14. Can adults have DPM1 deficiency? Yes, but many reported patients present in infancy or childhood. [3][6]
15. What is the best overall treatment? Early, multidisciplinary, complication-focused care. [4][5]
Disclaimer: Each person’s journey is unique, treatment plan, life style, food habit, hormonal condition, immune system, chronic disease condition, geological location, weather and previous medical history is also unique. So always seek the best advice from a qualified medical professional or health care provider before trying any treatments to ensure to find out the best plan for you. This guide is for general information and educational purposes only. Regular check-ups and awareness can help to manage and prevent complications associated with these diseases conditions. If you or someone are suffering from this disease condition bookmark this website or share with someone who might find it useful! Boost your knowledge and stay ahead in your health journey. We always try to ensure that the content is regularly updated to reflect the latest medical research and treatment options. Thank you for giving your valuable time to read the article.
The article is written by Team RxHarun and reviewed by the Rx Editorial Board Members
Last Updated: April 01, 2025.
