Inborn errors of metabolism
An inherited urea cycle disorder. The body cannot get rid of the ammonia that comes from protein. Ammonia builds up in the blood and affects the brain.
Not part of the panel of Türkiye's National Newborn Screening Programme (heel-prick test). Source
Orphanet has a guideline for emergency doctors for this disease (language: French, English). See on Orphanet
This page is translated from the Turkish original.
This disease is followed through the “Inborn errors of metabolism” group.
Ammonia forms when the body uses protein. The liver turns it into harmless urea through the urea cycle. In this disease, one of the enzymes in the cycle is missing. Ammonia builds up in the blood and affects the brain most; the liver can also be damaged.
The disease can appear at any age. Its most severe form is seen in the first days, mostly in baby boys.
Ammonia in the blood is high. Blood and urine tests tell it apart from other diseases. The diagnosis is confirmed with a genetic test. In most places it is not part of routine newborn screening.
A low-protein, high-calorie diet is followed. Medicines that help remove ammonia from the body are used. In a severe episode, dialysis may be needed. In some people, a liver transplant may be considered. Research on gene therapy is ongoing. The doctor who follows the disease decides which treatment is suitable.
The disease is X-linked and mostly affects males. For each son of a carrier mother, the chance of being affected is 1 in 2. Half of her daughters will be carriers. Most women who are carriers are healthy; some have symptoms. In some children, the change does not come from the family but arises new. Genetic counselling guides the family.
Source: MedlinePlus Genetics: Ornithine transcarbamylase deficiency · NORD: Ornithine Transcarbamylase Deficiency
These facts are taken from Orphanet and MedlinePlus records (last checked: October 7, 2026). Frequency values are approximate ranges.
Non-profit patient and family organizations in Türkiye working on this disease or disease group. Links are for information; Doktorclub is not affiliated with these organizations and does not endorse them.
For all rare diseases: Nadir Hastalıklar Federasyonu
Links checked on October 8, 2026.
Doktorclub does not diagnose, recommend treatments or refer you to hospitals or doctors. These pages are meant to help you talk with your doctor.
JapanDiagnosis and screening
OTC deficiency is a urea cycle disorder that causes ammonia levels to rise, and it is hard to detect through screening.
A clinical trial is a regulated study that tests whether a new treatment is safe and whether it works, in patients who volunteer. Most trials look for a certain age, genetic change and health condition. Taking part is voluntary.
Questions you can ask your doctor
ClinicalTrials.gov lists 6 active interventional studies for this disease. 2 are recruiting now; none has a site in Türkiye. Last checked: October 7, 2026.
Selected records (studies with a site in Türkiye first):
Middle stage: the effect is being tested in a small group · Phase 2 · investigational (experimental)RecruitingNCT06488313
Middle stage: the effect is being tested in a small group · Phase 1 / Phase 2 · investigational (experimental)RecruitingNCT05092685
Late stage: the effect is being compared in a large group · Phase 3 · investigational (experimental)Active, not recruitingNCT06255782
Late stage: the effect is being compared in a large group · Phase 3 · investigational (experimental)Active, not recruitingNCT05345171
Middle stage: the effect is being tested in a small group · Phase 1 / Phase 2 · investigational (experimental)Not yet recruitingNCT07773246
See all studies on ClinicalTrials.gov · Joining clinical trials
EUNew treatments and approvals
In Europe, leriglitazone, taken by mouth, was authorized for cerebral adrenoleukodystrophy.
USANew treatments and approvals
Through the accelerated pathway, the FDA has approved pariglasgene brecaparvovec for glycogen storage disease type Ia.
EuropeResearch and clinical trials
A total of 58 patients from 34 centers in seven European countries were followed.
These codes identify the disease in international classifications and databases. They can help when you talk with your doctor or look for reliable sources.
Orphanet code: ORPHA:664
No separate ICD-11 code; WHO classifies this disease under: 5C50.AY
Codes checked against WHO ICD-11 and Orphanet on October 7, 2026.
This page provides general information and does not replace diagnosis or treatment. Talk to your doctor about symptoms, diagnosis and treatment.