Long-chain fatty acid oxidation disorders (LC-FAOD) are a rare metabolic condition that results in impaired fatty acid utilization, leading to metabolic crises, hospitalization, and reduced quality of life. Despite dietary management, many patients experience ongoing complications. Triheptanoin, a seven-carbon triglyceride, has emerged as a therapeutic alternative by providing an energy source and supporting metabolic stability. This study aims to evaluate the clinical outcomes of LC-FAOD patients receiving triheptanoin therapy in Türkiye. A retrospective nationwide study was conducted to analyze 14 patients with LC-FAOD who received oral triheptanoin as part of a compassionate use program in Türkiye. The study collected data on emergency department visits, hospitalizations, metabolic decompensation episodes, creatine kinase (CK) levels, hypoglycemia, and cardiac function. Additionally, patient-reported outcomes were assessed through surveys. The findings of the study demonstrated that triheptanoin treatment led to a significant reduction in the number of emergency service applications and hospitalizations per month (p < 0.01). A notable decrease in the frequency of myalgia attacks was observed, while the decline in rhabdomyolysis episodes did not reach statistical significance. Furthermore, creatine kinase levels during metabolic crises exhibited a substantial decrease following triheptanoin therapy (p < 0.0001).Among patients with cardiomyopathy, cardiac function showed improvement in four out of seven patients. Survey data indicated an improvement in appetite, physical performance, and overall quality of life. Conclusion: Triheptanoin treatment has been demonstrated to be associated with significant clinical improvements in patients diagnosed with LC-FAOD, including a reduction in the frequency of emergency department visits, hospitalizations, and metabolic crises. These findings provide support for the utilization of triheptanoin as a therapeutic approach that holds promise in the management of LC-FAOD. What is Known: • Long-chain fatty acid oxidation disorders (LC-FAOD) are associated with significant morbidity due to metabolic crises, despite conventional dietary treatment including medium-chain triglycerides (MCT). What is New: • This nationwide study demonstrates that triheptanoin therapy significantly reduces emergency visits, hospitalizations, and creatine kinase levels during crises, and improves patient-reported outcomes, including physical activity and quality of life, in LC-FAOD patients in Türkiye.

Background/Objectives: Phenylketonuria is a hereditary metabolic disorder characterized by a deficiency of phenylalanine hydroxylase. The main treatment for PKU is a phenylalanine-restricted diet. The exclusion of protein rich natural foods and inclusion of low-Phe substitutes may give rise to an imbalanced diet, and the increased risk of overweight and obesity in PKU is a cause for concern. We aimed to evaluate the body composition and nutritional biochemical biomarkers in adult PKU patients who are on Phe-restricted and essential amino acid-supplemented nutrition therapy and to investigate the relationships between these parameters and patient gender, adherence to dietary therapy, and disease type, defined as mild or classic PKU. Methods: The study group comprised 37 PKU patients and 26 healthy siblings as controls. The participants were assessed based on an analysis of anthropometric parameters, body composition, and biochemical test results. Results: PKU patients do not have a higher incidence of overweight and obesity than healthy controls, the proportion of energy derived from carbohydrates in their diets was below the recommended level, and their total energy intake was below the recommended daily allowance. It was remarkable that patients with a treatment adherence ratio of <50% displayed a higher prevalence of overweight and abdominal obesity in comparison to those with a more favorable treatment adherence ratio. Conclusions: In view of the growing prevalence of overweight in the general population, PKU patients should be kept under close long-term follow-up. Particularly in the group with low treatment compliance, more caution should be taken in terms of adverse outcomes.

Background: We aimed to evaluate the role of nutrition and behavior education intervention in the prevention and treatment of childhood obesity by comparing changes in obesity-related characteristics among obese children during a follow-up period of 12 months. Methods: This study was designed as a prospective cohort study in children aged between 6 and 18 years, with exogenous obesity who applied to Istanbul Research and Training Hospital, Pediatrics Department, between January 2018 and July 2019. Beginning at the sixth month, a program for nutrition and behavior education for obesity prevention and treatment was initiated and continued during the second half of the study period. Results: The mean age of 59 children (29 females, 30 males) was 11.73 ± 2.78. BMI levels did not show a significant difference in the first 6 months, but decreased significantly during the second 6 months of the study. Screen time, fast eating behavior, overeating behavior and food score index scores also demonstrated significant improvements during the intervention period of the study, between 6 and 12 months. Conclusion: It was concluded that nutrition and behavior education for the prevention and treatment of childhood obesity could be a successful intervention with close follow-up.

Background: Phenylketonuria is an autosomal recessive disorder characterized by the deficiency of phenylalanine hydroxylase, which converts phenylalanine into tyrosine. Diagnosis and prompt initiation of appropriate treatment shortly after birth are important for achieving optimal outcomes in phenylketonuria. IDMP-PKU is an ongoing study to gain insight into the patient journey and identify the unmet needs and areas for improvement in diagnosis, treatment, and follow-up of PKU in Türkiye. Aim: To present the rationale and design of the IDMP-PKU study, as well as the findings from an interim analysis, describing baseline demographic, diagnosis, family history, and genetic testing data for 1553 children enrolled in the study. Method: This is a multicenter, observational registry-based study, conducted in 3 tertiary pediatric metabolic clinics in Türkiye. The study provides a descriptive analysis of baseline demographic, diagnosis, family history, and genetic testing data of study population. Results: The study included 1,553 patients (median age: 10 (IQR 5–18) years; 37.1% classical PKU) from 90% of the cities in Türkiye, diagnosed between 1981 and 2022. Parental consanguinity was reported in 43.5% of families (27.1% first cousins). The most frequently detected allelic variant was c.1066-11G > A (IVS-10-11G > A) (22.8%). Homozygous mutations were more common in patients with parental consanguinity (76.8% vs 17.1%; p < 0.001). The median time to diagnosis improved to 21 days after the implementation of the national newborn screening (NBS) program in December 2006 but 28.6% of patients were diagnosed after one month of age. Low level of maternal education was associated with longer time to diagnosis (p < 0.001). Conclusions: Implementation of national NBS has contributed to earlier identification of patients with PKU. Increasing the number of screening laboratories and pediatric metabolic clinics will speed up the diagnostic process and help achieve the guideline-recommended time for diagnosis and initiation of treatment. In countries with high rates of consanguineous marriages, increasing public awareness of PKU and genetic counselling before marriage will be valuable in reducing the prevalence of PKU.

Carnitine palmitoyltransferase I (CPT I) deficiency is an autosomal recessive disorder causing long-chain fatty acid oxidation defect, characterized by metabolic decompensation episodes accompanied by hypoketotic hypoglycemia, hepatomegaly, seizures, renal tubular acidosis, and hyperammonemia. The aim of this study was to investigate the neurological symptoms in CPT I deficiency and different outcomes with respect to predisposing factors for sequela and to draw attention to the neurological impairment that may develop during the course of the disease. The retrospective study reviewed clinical characteristics of 14 patients. Mean follow-up period was 10.3 ± 4.7 (range: 8 months-18.6 years; median: 10 years) years. Three patients were diagnosed with newborn screening. In the symptomatic group (n = 12) most common presenting symptoms were psychomotor retardation (n = 6), seizures (n = 5), encephalopathy (n = 5), dystonia (n = 1), Reye-like syndrome (n = 5), muscle weakness (n = 3), and autism (n = 1). Neurologic findings detected in the follow-up period included speech disorder (n = 9), abnormal cranial MRI findings (n = 5), neuropathy (n = 1), and attention deficit hyperactivity disorder (n = 1). Speech disorders collectively included delayed expressive language development, speech articulation disorder, speech delay, stuttering, and specific speech difficulties. After starting treatment for CPT I deficiency, speech disorders improved in 3 patients. Our findings confirmed that the clinical manifestations of CPT I deficiency is wider than previously thought, causing specific neurologic dysfunction, mainly speech disorders at a large scale, that were unexpected in a fatty acid oxidation disorder. We suggest that early diagnosis and treatment is the key factor to prevent neurologic sequelae while an extensive neurological evaluation is essential in patients with CPT I deficiency both at the time of diagnosis and during the follow-up period.

Objectives: There is growing concern about the low-protein and high-energy diet therapies used in the treatment of inherited amino acid metabolism disorders. We aimed to identify the risk factors for noncommunicable diseases that may arise from nutritional therapies and suggests approaches that may prevent the development of the noncommunicable diseases. Methods: The present study evaluates 112 patients, on long-term nutritional therapy for at least the last 2 years with a diagnosis of an inborn error of the amino acid metabolism, and their 28 healthy siblings. The participants are assessed for the development of overweight and metabolic syndrome based on an analysis of anthropometric parameters, body composition and the results of biochemical tests. Results: Anthropometric measurements including BMI, weight Z-score, waist circumference and fat mass were not significantly different between patients and controls. Height Z-scores were similar in phenylketonuria patients compared to controls, but lower in urea cycle disorders, organic acidemia and maple syrup urine disease groups. No increased risk of development of overweight or metabolic syndrome was detected in the patient group, while there were findings suggesting malnutrition in patients diagnosed with urea cycle disorders. There was a correlation between patients’ BMI and C3-carnitine levels in organic acidemia patients and leucine levels in maple syrup urine disease patients. Conclusions: All forms of malnutrition can be prevented in patient groups receiving limited nutrients under a dietary management protocol, based on the findings of anthropometric and biochemical evaluations and analyses of body composition.