Inborn errors of metabolism
A urea cycle disease. The body cannot get rid of ammonia formed from protein. It can be severe in the newborn period.
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: English, French). See on Orphanet
This page is translated from the Turkish original.
This disease is followed through the “Inborn errors of metabolism” group.
When proteins are broken down, ammonia forms in the body. Normally the liver turns it into urea, which leaves the body in urine. In this disease, the enzyme for the first step of this cycle does not work. Ammonia builds up in the blood and harms the brain most of all.
In the severe type, symptoms begin a few days after birth. In some people, the disease is milder and can begin at any age. Fasting, another illness or too much protein can cause a sudden worsening.
When the doctor suspects the disease from the symptoms, ammonia in the blood is measured. The levels of certain amino acids in the blood are also checked. The diagnosis is confirmed with a genetic test.
In severe episodes, the aim is to lower the ammonia in the blood quickly. This can be done in hospital with methods such as dialysis. In the long term, a special diet with limited protein is followed for life. Medicines that help remove ammonia and, for some babies, a liver transplant are also among the options. The doctor who follows the disease decides which treatment is suitable.
The disease is passed on through recessive inheritance. The mother and father are often healthy carriers. For a couple who are both carriers, the chance of having an affected child is 1 in 4 in each pregnancy. Genetic counselling is recommended for brothers and sisters and for future pregnancies.
Source: MedlinePlus Genetics — Carbamoyl phosphate synthetase I deficiency · Orphanet — Carbamoyl-phosphate synthetase 1 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.
USAResearch and clinical trials
In the USA, a baby named KJ with severe CPS1 deficiency received an individualized base-editing therapy.
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. 3 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 1 / Phase 2 · investigational (experimental)RecruitingNCT07667387
Late stage: the effect is being compared in a large group · Phase 3 · investigational (experimental)Active, not recruitingNCT06255782
Middle stage: the effect is being tested in a small group · Phase 1 / Phase 2 · investigational (experimental)Not yet recruitingNCT07773246
Non-drug study (device, procedure, care, etc.)RecruitingNCT06953505
Non-drug study (device, procedure, care, etc.)RecruitingNCT05671666
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:147 · ICD-11 5C50.A1
Codes checked against WHO ICD-11 and Orphanet on October 6, 2026.
This page provides general information and does not replace diagnosis or treatment. Talk to your doctor about symptoms, diagnosis and treatment.