Researchers in Eastern Turkey found that newborn screening programs successfully catch about 7 out of 10 cases of inherited metabolic disorders, genetic diseases that affect how the body processes nutrients. In a study of 9,603 patients, 8.6% had confirmed metabolic disorders, with biotinidase deficiency (a biotin processing problem) being the most common, found in 43% of cases. According to Gram Research analysis, newborn screening combined with careful observation of sick patients provides the best chance of catching these rare diseases early, when treatment works best.
Researchers in Eastern Turkey studied over 9,600 patients to understand which inherited metabolic disorders (genetic diseases that affect how the body processes nutrients) are most common in their region. They found that 8.6% of patients had these disorders, with most cases caught through newborn screening programs. The most common disorder was biotinidase deficiency, a condition where babies can’t process biotin (a B vitamin) properly. According to Gram Research analysis, newborn screening and checking sick patients work together to catch these rare diseases early, when treatment can make the biggest difference.
Key Statistics
A 2026 study of 9,603 patients in Eastern Turkey found that newborn screening programs identified 70% of inherited metabolic disorders before symptoms appeared, while 28% were diagnosed only after patients became sick.
Biotinidase deficiency was the most common inherited metabolic disorder in the study, accounting for 43.4% of all 828 confirmed cases, with 87.8% being partial deficiency and 12.2% being profound deficiency.
Among 9,603 patients evaluated at a tertiary center in Eastern Turkey between 2022 and 2024, 8.6% had confirmed inherited metabolic disorders, with vitamin and cofactor metabolism disorders being most frequent at 43.8% of cases.
The estimated birth prevalence of biotinidase deficiency in Eastern Turkey was 1 per 543 newborns, and hyperphenylalaninemia/phenylketonuria spectrum was 1 per 627 newborns, based on analysis of 61,409 live births.
The Quick Take
- What they studied: Which genetic diseases that affect how the body processes nutrients are most common in Eastern Turkey, and how well do newborn screening tests catch them compared to finding them when babies get sick.
- Who participated: 9,603 patients evaluated at a major hospital in Eastern Turkey between September 2022 and September 2024. Most were newborns screened at birth, but some were older children and adults who came to the hospital because they were sick.
- Key finding: About 1 in 12 patients (8.6%) had an inherited metabolic disorder. Newborn screening caught 70% of cases before symptoms appeared, while 28% were found because patients got sick. Biotinidase deficiency was the most common disorder, found in 43% of all cases.
- What it means for you: If you live in or have family from Eastern Turkey, newborn screening is catching most genetic metabolic diseases early, which is good news because early treatment prevents serious problems. However, some cases are still missed, so parents should watch for unusual symptoms like poor feeding, developmental delays, or seizures in newborns.
The Research Details
This was a retrospective study, meaning researchers looked back at medical records from patients already treated at a major hospital in Eastern Turkey. They reviewed 9,603 patient records collected over two years (September 2022 to September 2024) and identified which patients had confirmed inherited metabolic disorders. Confirmation required lab tests that measured specific chemicals in blood or urine, or genetic testing that looked at DNA. The researchers then used birth records from the region to calculate how common each disease is among newborns. This approach let them see both which diseases newborn screening programs catch and which ones only get diagnosed when patients develop symptoms and seek medical care.
Understanding which genetic metabolic diseases are most common in a specific region helps doctors know what to screen for and what symptoms to watch for. Different populations have different disease patterns based on genetics and ancestry. By studying this particular region, the researchers provided information that can help local doctors improve their screening and diagnosis practices. The study also shows that newborn screening and symptom-based diagnosis work together: screening catches many cases early, but some diseases still need to be caught through careful observation of sick patients.
This study has good reliability because it included a large number of patients (over 9,600) and used confirmed diagnoses based on lab tests and genetic analysis, not just guesses. The researchers used actual birth records to calculate disease frequency, which is more accurate than estimates. However, because this was a retrospective study looking at past records, the researchers couldn’t control all the factors that might affect results. The study was done at one hospital, so results may not apply to all of Turkey or other countries. The study period was relatively short (2 years), so rare diseases might not have shown up.
What the Results Show
Among 9,603 patients evaluated, 828 had confirmed inherited metabolic disorders, which is about 1 in 12 patients (8.6%). Of these 828 cases, newborn screening programs caught 580 cases (70%), symptomatic referral (patients coming to the hospital because they were sick) found 230 cases (28%), and family screening found 18 cases (2%). The most common type of disorder involved problems with vitamin and cofactor metabolism (43.8% of all cases), followed by amino acid metabolism disorders (35.7%). Biotinidase deficiency was by far the most frequent single disorder, found in 360 patients (43.4% of all cases). Of these biotinidase cases, most (87.8%) were partial deficiency (less severe), while 12.2% were profound deficiency (more severe). Among patients who came to the hospital because they were sick, neurological problems (issues with the brain and nervous system) were the most common sign, appearing in 23.2% of symptomatic patients.
The researchers calculated how common specific diseases are in the region based on live birth numbers. Hyperphenylalaninemia and phenylketonuria (PKU), disorders affecting how the body processes the amino acid phenylalanine, occurred in about 1 out of every 627 newborns. Biotinidase deficiency occurred in about 1 out of every 543 newborns. Rarer diseases like mucopolysaccharidoses (disorders affecting how the body breaks down complex sugars) occurred in about 1 per 100,000 people, and alkaptonuria (a disorder affecting amino acid breakdown) occurred in about 1 per 100,000 people. These numbers show that while some metabolic disorders are relatively common in this region, others are quite rare.
This study adds important information about disease patterns in Eastern Turkey, a region where fewer studies have been done compared to Western Europe and North America. The high frequency of biotinidase deficiency (43.4% of all cases) is notable and may reflect the genetic background of the population. The finding that newborn screening catches 70% of cases aligns with what other countries have found: screening programs are effective but not perfect, and symptomatic diagnosis remains important. The study confirms what researchers have found elsewhere: that vitamin and cofactor metabolism disorders are common causes of inherited metabolic disease.
This study looked at patients at one hospital, so results may not represent all of Eastern Turkey or other regions. The study only covered 2 years, so very rare diseases might not have appeared in the data. Because it was retrospective (looking at past records), the researchers couldn’t control how carefully doctors looked for these diseases or whether some cases were missed. The study doesn’t tell us about patients who were never diagnosed or who died before reaching the hospital. Different hospitals might have different screening practices, which could affect which diseases get caught. The study also doesn’t include information about how well patients did with treatment or how their lives changed after diagnosis.
The Bottom Line
Newborn screening for metabolic disorders should continue and be maintained as a priority in Eastern Turkey, as it successfully catches 70% of cases before symptoms develop. High confidence: Families with a history of metabolic disorders should ask about genetic counseling and carrier testing. Moderate confidence: Doctors should remain alert for symptoms of metabolic disorders in children with developmental delays, seizures, or unexplained illness, since 28% of cases are still caught through symptomatic diagnosis. Moderate confidence: Parents of newborns should ensure their babies receive all recommended screening tests at birth.
Parents and expectant parents in Eastern Turkey should care about this research because it shows newborn screening is working well in their region. Doctors and pediatricians should use this information to understand which diseases are most common locally and what symptoms to watch for. Families with a history of metabolic disorders should be aware that genetic counseling is available. People planning to have children and those with family history of genetic diseases should discuss screening options with their doctors. This research is less directly relevant to people in other countries, though the methods used could be applied elsewhere.
Newborn screening results typically come back within 1 to 2 weeks after birth. If a baby has an abnormal screening result, follow-up testing happens within days to weeks. Treatment can begin immediately after diagnosis, and many metabolic disorders can be managed effectively with diet changes, supplements, or medications started early. For symptomatic patients, the timeline depends on when symptoms appear and when diagnosis is made, which is why early recognition of symptoms is important. Long-term management requires ongoing monitoring throughout life.
Frequently Asked Questions
What is biotinidase deficiency and why is it so common in Turkey?
Biotinidase deficiency is a genetic disorder where the body can’t process biotin (vitamin B7) properly, leading to neurological problems if untreated. It’s the most common metabolic disorder in this Turkish region (43% of cases), likely due to the genetic background of the population. Early treatment with biotin supplements prevents serious complications.
How effective is newborn screening for catching metabolic disorders?
Newborn screening caught 70% of inherited metabolic disorders in this study before symptoms appeared, making it highly effective. However, 28% of cases were still missed and only diagnosed when patients got sick, showing that screening isn’t perfect and doctors must remain alert for symptoms.
What symptoms should parents watch for if they suspect a metabolic disorder?
Parents should watch for poor feeding, vomiting, developmental delays, seizures, muscle weakness, or unusual behavior in newborns and young children. Neurological symptoms were the most common presentation in symptomatic patients (23.2%). Any concerning symptoms warrant immediate medical evaluation.
Can inherited metabolic disorders be treated?
Many inherited metabolic disorders can be effectively managed with early diagnosis and treatment. Common approaches include specialized diets, vitamin or mineral supplements, and medications. Early treatment started through newborn screening prevents serious complications and improves long-term outcomes significantly.
Should I get genetic testing if metabolic disorders run in my family?
Yes, genetic counseling and carrier testing are recommended if metabolic disorders run in your family. This helps you understand your risk, make informed reproductive decisions, and ensures any children receive appropriate newborn screening and early treatment if needed.
Want to Apply This Research?
- If a user has a family history of metabolic disorders or a child with a confirmed diagnosis, they should track dietary intake (especially protein and specific amino acids), supplement compliance, and any symptoms like fatigue, developmental changes, or neurological signs. Weekly check-ins on whether prescribed supplements were taken as directed would be valuable.
- Users with a family history of metabolic disorders should use the app to set reminders for genetic counseling appointments and carrier testing. Parents of diagnosed children should use the app to log meals and track adherence to specialized diets (low-protein diets are common for amino acid disorders). Users should set reminders for regular follow-up appointments with metabolic specialists.
- Long-term tracking should include quarterly reviews of lab test results (blood and urine metabolite levels), medication and supplement adherence, dietary compliance, and developmental milestones for children. The app should flag when follow-up appointments or lab tests are due. Users should track any new symptoms or health changes and share this data with their metabolic specialist during appointments.
This research describes patterns of inherited metabolic disorders in Eastern Turkey and should not be used for self-diagnosis. Inherited metabolic disorders are serious medical conditions requiring professional diagnosis and treatment. If you suspect your child has a metabolic disorder based on symptoms like poor feeding, developmental delays, seizures, or unusual behavior, seek immediate medical evaluation. Newborn screening results require confirmation through additional testing by a metabolic specialist. This article is for educational purposes and does not replace professional medical advice. Always consult with a qualified healthcare provider or metabolic specialist for diagnosis, treatment, and management of inherited metabolic disorders.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.