Four cases of Chanarin-Dorfman syndrome presenting with different types of erythrokeratoderma.

Chanarin-Dorfman syndrome (CDS) is a multisystem autosomal recessive disorder due to variants of the ABHD5 gene, characterized by lipid vacuoles in the liver and leukocytes, and possible involvement of eyes, ears, skeletal muscle, and central nervous system. CDS may present with skin changes, most commonly congenital non- bullous ichthyosiform erythroderma, however erythrokeratoderma-like findings have been rarely reported in CDS patients. Herein, we report clinical, histopathological and genetic findings of four patients with CDS presenting with different clinical forms of erythrokeratoderma (three with progressive symmetric erythrokeratoderma-like features and one with erythrokeratoderma variabilis (EKV)-like features), including one patient with a novel mutation in ABHD5. Although the typical skin finding of CDS syndrome is reported as non-bullous congenital ichthyosiform erythroderma, CDS should also be in the differential diagnosis in patients with EKV-like lesions.

Neuronal ceroid lipofuscinosis: genetic and phenotypic spectrum of 14 patients from Turkey.

INTRODUCTION AND PURPOSE: Neuronal ceroid lipofuscinoses (NCLs) is a group of congenital metabolic diseases where the neurodegenerative process with the accumulation of ceroid and lipofuscin autofluorescent storage materials is at the forefront. According to the age of presentation, NCLs are classified as congenital, infantile (INCL), late infantile (LINCL), juvenile (JNCL), and adult (ANCL) NCLs. In our study, it was aimed to discuss the clinical and molecular characteristics of our patients diagnosed with NCL. MATERIAL AND METHOD: This is a descriptive cross-sectional study which was conducted in 14 patients from 10 unrelated families who were diagnosed with different types of NCL based on clinical presentation, neuroimaging, biochemical measurements, and molecular analyses, at the department of pediatric metabolism between June 2015 and June 2020. RESULTS: A total of 14 patients were diagnosed with different types of NCL. Of those, 4 patients were diagnosed with NCL7 (4/14; 30%), 3/14 (23%) with NCL1, 3/14 (23%) with NCL2, 2/14 (14.2%) with NCL13, and 1/14 (7.1%) with NCL10. Eleven pathogenic variants were detected, 5 of which are novel (c.721G>T [p.Gly241Ter] and c.301G>C [p.Ala146Pro] in MFDS8 gene; c.316C>T [p.Gln106Ter] in PPT1 gene; c.341C>T [p.Ala114Val] in TPP1 gene; c.686A>T [p.Glu229Val] in CTSD gene) CONCLUSION: This study is one of the pioneer comprehensive researches from Turkey that provides information about disease-causing variants and clinical presentation of different and rare types of NCLs. The identification of novel variants and phenotypic expansion is important for genetic counselling in Turkey and expected to improve understanding of NCLs.

Experience with carnitine palmitoyltransferase II deficiency: diagnostic challenges in the myopathic form.

OBJECTIVES: Carnitine palmitoyltransferase II (CPT II) deficiency is an autosomal recessive disorder of long-chain fatty acid oxidation. Three clinical phenotypes, lethal neonatal form, severe infantile hepatocardiomuscular form, and myopathic form, have been described in CPT II deficiency. The myopathic form is usually mild and can manifest from infancy to adulthood, characterised by recurrent rhabdomyolysis episodes. The study aimed to investigate the clinical features, biochemical, histopathological, and genetic findings of 13 patients diagnosed with the myopathic form of CPT II deficiency at Ege University Hospital. METHODS: A retrospective study was conducted with 13 patients with the myopathic form of CPT II deficiency. Our study considered demographic data, triggers of recurrent rhabdomyolysis attacks, biochemical metabolic screening, and molecular analysis. RESULTS: Ten patients were examined for rhabdomyolysis of unknown causes. Two patients were diagnosed during family screening, and one was diagnosed during investigations due to increased liver function tests. Acylcarnitine profiles were normal in five patients during rhabdomyolysis. Genetic studies have identified a c.338C>T (p.Ser113Leu) variant homozygous in 10 patients. One patient showed a novel frameshift variant compound heterozygous with c.338C>T (p.Ser113Leu). CONCLUSIONS: Plasma acylcarnitine analysis should be preferred as it is superior to DBS acylcarnitine analysis in diagnosing CPT II deficiency. Even if plasma acylcarnitine analysis is impossible, CPT2 gene analysis should be performed. Our study emphasizes that CPT II deficiency should be considered in the differential diagnosis of recurrent rhabdomyolysis, even if typical acylcarnitine elevation does not accompany it.

Glutaric aciduria and L-2-hydroxyglutaric aciduria: Clinical and molecular findings of 35 patients from Turkey.

Background: Cerebral organic acid disorders are progressive neurometabolic diseases characterized by neurologic dysfunction. Glutaric aciduria type I (GA-I) and L-2-hydroxyglutaric aciduria (L2HGA) are the main cerebral organic acid disorders. They are both classified as, and it is suggested that these two disorders may share a common metabolic pathway. Current treatment strategies are based on levocarnitine, vitamin B2, and diet. Recent guidelines recommend a lysine-restricted diet up to six years of age, but there is no consensus for patients over the age of six. Vitamin B2 is exists in the blood as riboflavin and its cofactors, flavin mononucleotide and flavin adenine dinucleotide (FAD). FAD, the cofactor of L2HGD, accelerates the conversion of L-2-hydoxy glutarate to alpha-ketoglutarate. Levocarnitine stimulates the formation and excretion of derivatives of glutaric acid. Also, lysine-associated organic acidurias some results provide principal proof for the beneficial effects of riboflavin in GA-I. It has been previously reported that combination therapy with riboflavin and levocarnitine is effective for L2HGA as well as GA-I. Riboflavin and levocarnitine have been reported to improve not only clinical symptoms but also urinary 2-HGA levels. In our study, we aimed to evaluate the effect of the current treatment strategies and genotype on urinary metabolites and IQ scores in GA-I and L2HGA patients. Methods: The presented retrospective multicenter study included patients followed up in Diyarbakir Children's Hospital and Izmir Katip Celebi University Faculty of Medicine, Division of Pediatric Metabolism. Between 2016 and 2021, we retrospectively evaluated 35 patients with confirmed diagnosis of GA-I and L-2HGA. We analyzed the clinical, biochemical, neuroradiological, molecular data and treatment of the patients. The follow-up period was every 2 months until 12 months old, every 3 months until 6 years of age, and every 6 months thereafter. Therapy monitoring was undertaken during follow-up visits that included evaluation of clinical parameters, laboratory parameters, and dietary consumption records. Denver II was applied in order to evaluate children aged 0-6 years in terms of development. Patients between 6 and 16 years of age were evaluated using the Wechsler Intelligence Scale for Children-Revised. Results: We identified 25 with GA-I and 10 with L2HGA. The most common clinical symptoms were developmental delay, intellectual disability, and movement disorders. Behavioural problems were more common in L2HGA than in GA-I patients. In the same family, there were patients with severe developmental delay despite early diagnosis and treatment and individuals with normal IQ scores. In our study group, we used diet (lysine restricted or protein controlled), levocarnitine and vitamin B2 for GA-I patients. The mean urinary glutaric acid levels were decreased with treatment in GA-I patients. Group I consisted of 14/25 patients receiving lysine restricted diet and levocarnitine, Group II (8/25) received protein-controlled diet and levocarnitine. Group III (3/25) patients whom had p.Pro248Leu (P248L) variant, received riboflavin in combination with protein-controlled diet and levocarnitine. When we evaluated according to the treatment groups, a significant decrease was observed in urinary glutaric acid levels in group I. But there were no significant difference in Group II and III. The patients with c.1018C > T variant in GCDH gene had higher pre-treatment urinary metabolites and significant reduction in urinary metabolites with treatment was detected. In L2HGA patients, we used levocarnitine and vitamin B2. In all L2HGA patients, there was a significant decrease in the mean urinary 2- hydoxy glutarate with treatment. However, there was no significant difference between the c.164G > A and c.1115delT variants. The mean pre- and post-treatment IQ scores of GA-I patients, no significant difference was observed. Relative neurologic improvement was seen in three L2HGA patients. We found two novel variants, including the c.221A > G (p.Tyr74Cys) in the GCDH gene and the c.738 + 5A > G splice variant in the L2HGDH gene. Conclusions: Glutaric aciduria type I and L2HGA are the most common cerebral organic acidurias. Early and correct diagnosis is crucial. Poor prognosis based on metabolic crises and progressive deterioration still appears. In countries where newborn screening is not performed, a clinical suspicion index is required for cerebral organic aciduria. GA-I and L-2HGA are difficult to examine by medical evidence standards because of the small sample size, regional differences in newborn screening, and medical care limits. More clinical studies are needed to identify effective treatments. However, the significant decrease in urinary glutaric acid levels after treatment in patients on lysine-restricted diet raises the question of whether lysine-restricted diet should be continued after six years of age. We also reported our experience in order to contribute to the literature.

A female case of 5,10-methenyltetrahydrofolate synthetase deficiency with novel neuro-imaging abnormalities.

BACKGROUND: Folate metabolism disorders can affect various organ systems, including the nervous system. 5,10-methenyltetrahydrofolate synthetase deficiency is a rare cerebral folate deficiency in which MTHFS activity is disrupted with low-normal cerebrospinal fluid (CSF) 5,10-methenyltetrahydrofolate levels, while peripheral folate levels are normal. CASE REPORT: We present here a female patient with developmental delay, microcephaly, hypotonia, nystagmus, and seizure in which a distinct brain MRI and CT showed restricted diffusion in the bilateral parietal and occipital lobes, and calcifications of the bilateral putamen, globus pallidus, and caudate nucleus, and the bilateral parietal and occipital lobes. Laboratory tests revealed macrocytic anemia, increased homocysteine, low-normal CSF 5,10-methenyltetrahydrofolate, and low CSF folate, but normal serum vitamin B12 and folate levels. A whole exome sequencing analysis verified the diagnosis of 5,10-methenyltetrahydrofolate synthetase deficiency. CONCLUSIONS: We have added novel knowledge which is nystagmus and hypotonia in the clinical findings, the involvement and restriction of bilateral putamen, globus pallidus, parietal and occipital lobes, and calcification of the bilateral putamen, globus pallidus, caudate nucleus, and parietal and occipital lobes in neuroimaging images and also low CSF folate in the metabolic investigation with the patient in 5,10-methenyltetrahydrofolate synthetase deficiency.

Clinical spectrum of early onset "Mediterranean" (homozygous p.P131L mutation) mitochondrial neurogastrointestinal encephalomyopathy.

Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is an autosomal recessive mitochondrial disorder characterized by cumulative and progressive gastrointestinal and neurological findings. This retrospective observational study, aimed to explore the time of presentation, diagnosis and clinical follow-up of 13 patients with a confirmed MNGIE disease of Mediterranean origin. The mean age of symptom onset was 7 years (6 months-21 years) and the average diagnosis age was 15.4 years ±8.4. Four of 13 patients (30%) died before 30 years at the mean age of 19.7 years ±6.8. Cachexia and gastrointestinal symptoms were observed in all patients (100%). The mean body mass index standard deviation score at diagnosis was 4.8 ± 2.8. At least three subocclusive episodes were presented in patients who died in last year of their life. The main neurological symptom found in most patients was peripheral neuropathy (92%). Ten patients (77%) had leukoencephalopathy and the remaining three patients without were under 10 years of age. The new homozygous "Mediterranean" TYMP mutation, p.P131L (c.392 C > T) was associated with an early presentation and poor prognosis in nine patients (69%) from five separates families. Based on the observations from this Mediterranean MNGIE cohort, we propose that the unexplained abdominal pain combined with cachexia is an indicator of MNGIE. High-platelet counts and nerve conduction studies may be supportive laboratory findings and the frequent subocclusive episodes could be a negative prognostic factor for mortality. Finally, the homozygous p.P131L (c.392 C > T) mutation could be associated with rapid progressive disease with poor prognosis.

Tetrahydrobiopterin deficiencies: Lesson from clinical experience.

OBJECTIVES: The present study describes clinical, biochemical, molecular genetic data, current treatment strategies and follow-up in nine patients with tetrahydrobiopterin (BH4) deficiency due to various inherited genetic defects. METHODS: We analyzed clinical, biochemical, and molecular data of nine patients with suspected BH4 deficiency. All patients were diagnosed at Ege University Faculty of Medicine in Izmir, Turkey and comprised data collected from 2006 to 2019. The diagnostic laboratory examinations included blood phenylalanine and urinary or plasma pterins, dihydropteridine reductase (DHPR) enzyme activity measurement in dried blood spots, folic acid and monoamine neurotransmitter metabolites in cerebrospinal fluid, as well as DNA sequencing. RESULTS: Among the nine patients, we identified one with autosomal recessive GTP cyclohydrolase I (ar GTPCH) deficiency, two with 6-pyruvoyl-tetrahydropterin synthase (PTPS) deficiency, three with sepiapterin reductase (SR) deficiency, and three with DHPR deficiency. Similar to previous observations, the most common clinical symptoms are developmental delay, intellectual disability, and movement disorders. All patients received treatment with l-dopa and 5-hydroxytryptophan, while only the ar GTPCH, the PTPS, and one DHPR deficient patients were supplemented in addition with BH4. The recommended dose range varies among patients and depends on the type of disease. The consequences of BH4 deficiencies are quite variable; however, early diagnosis and treatment will improve outcomes. CONCLUSIONS: As BH4 deficiencies are rare group of treatable neurometabolic disorders, it is essential to diagnose the underlying (genetic) defect in newborns with hyperphenylalaninemia. Irreversible brain damage and progressive neurological deterioration may occur in untreated or late diagnosed patients. Prognosis could be satisfying in the cases with early diagnose and treatment.

Clinical and molecular characteristics and time of diagnosis of patients with classical galactosemia in an unscreened population in Turkey.

Classical galactosemia is an autosomal recessive inborn error of metabolism caused by biallelic pathogenic variants in the GALT gene. With the benefit of early diagnosis by newborn screening, the acute presentation of galactosemia can be prevented. In this study, we describe the clinical phenotypes, time of diagnosis and GALT genotypes of 76 galactosemia patients from Turkey, where the disease is not yet included in the newborn screening program. The median age at first symptom was 10 days (range 5-20), while the median age at diagnosis was 30 days (range 17-53). Nearly half of the patients (36 patients, 47.4%) were diagnosed later than age 1 month. Fifty-eight individuals were found to have 18 different pathogenic variants in their 116 mutant alleles. In our sample, Q188R variant has the highest frequency with 53%, the other half of the allele frequency of the patients showed 17 different genotypes. Despite presenting with typical clinical manifestations, classical galactosemia patients are diagnosed late in Turkey. Due to the geographical location of our country, different pathogenic GALT variants may be seen in Turkish patients. In the present study, a clear genotype-phenotype correlation could not be established in patients.

Single center experience of biotinidase deficiency: 259 patients and six novel mutations.

Background Biotinidase deficiency (BD) is an autosomal recessively inherited disorder of biotin recycling. It is classified into two levels based on the biotinidase enzyme activity: partial deficiency (10%-30% enzyme activity) and profound deficiency (0%-10% enzyme activity). The aims of this study were to evaluate our patients with BD, identify the spectrum of biotinidase (BTD) gene mutations in Turkish patients and to determine the clinical and laboratory findings of our patients and their follow-up period. Methods A total of 259 patients who were diagnosed with BD were enrolled in the study. One hundred and forty-eight patients were male (57.1%), and 111 patients were female (42.9%). Results The number of patients detected by newborn screening was 221 (85.3%). By family screening, 31 (12%) patients were diagnosed with BD. Seven patients (2.7%) had different initial complaints and were diagnosed with BD. Partial BD was detected in 186 (71.8%) patients, and the profound deficiency was detected in 73 (28.2%) patients. Most of our patients were asymptomatic. The most commonly found variants were p.D444H, p.R157H, c.98_104delinsTCC. The novel mutations which were detected in this study are p.D401N(c.1201G>A), p.A82G (c.245C>G), p.F128S(c.383T>C), c617_619del/TTG (p.Val207del), p.A287T(c.859G>A), p.S491H(c.1471A>G). The most common mutation was p.R157H in profound BD and p.D444H in partial BD. All diagnosed patients were treated with biotin. Conclusions The diagnosis of BD should be based on plasma biotinidase activity and molecular analysis. We determined the clinical and genetic spectra of a large group of patients with BD from Western Turkey. The frequent mutations in our study were similar to the literature. In this study, six novel mutations were described.