Mutation spectrum of 260 dystrophinopathy patients from Turkey and important highlights for genetic counseling.

We genetically evaluated 260 dystrophinopathy patients from Turkey. Karyotyping as an initial test in female patients, followed stepwise by multiplex ligation-dependent probe amplification and by targeted next-generation sequencing of DMD revealed definitive genetic diagnoses in 214 patients (82%), with gross deletions/duplications in 153 (59%), pathogenic sequence variants in 60 (23%), and X-autosome translocation in one. Seven of the gross and 27 of the sequence variants found novel. In silico prediction, co-segregation and transcript assays supported the pathogenic nature of the novel silent (p.Lys534=) and the splice site (c.4345-12C>G) alterations. From a total of 189 singleton cases, 154 (82%) had pathogenic alterations. From 138 of those who had maternal carrier testing, 68 out of 103 (66%) showed gross and 11 out of 35 (31%) showed small pathogenic variants. This suggests that the de novo occurrences in DMD appear approximately 2.1 times more frequently in meiotic unequal crossing-over than in uncorrected replication errors. Our study also disclosed three mothers as obligate gonadal mosaic carriers. Family-based investigation of dystrophinopathy patients is crucial for the ascertainment of novel or rare variants and also for counseling and follow-up care of the families.

Pregnancy management and outcome in patients with four different tetrahydrobiopterin disorders.

INTRODUCTION: Inborn errors of tetrahydrobiopterin (BH4) biosynthesis or recycling are a group of very rare neurometabolic diseases. Following growing awareness and improved availability of drug treatment the number of patients with BH4 disorders reaching adulthood is constantly increasing. Pregnancy care of patients with these disorders is therefore a new challenge for clinicians. METHODS: This retrospective study summarises for the first time clinical and biochemical monitoring data of 16 pregnancies in seven women with different disorders of BH4 metabolism and evaluates treatment regimens before and during pregnancy in relation to the obstetrical outcome and paediatric follow-up. RESULTS: Worsening of pre-existing neurological symptoms or occurrence of new symptoms during pregnancy was not observed in most of the cases. Treatment regimens remained mostly unchanged. Pregnancies were not complicated by disease-specific features. Organ abnormalities, miscarriage, prematurity, IUGR and chromosomal changes were occasionally reported, without showing any association with the standard drug treatment for BH4 deficiencies. CONCLUSION: Although our data on 16 pregnancies in seven patients did not present any association of standard drug treatment with an increased rate of pregnancy complications, abnormal obstetrical or paediatric outcome, an intensive clinical and biochemical supervision by a multidisciplinary team before, during and after the pregnancy in any BH4 deficiency is essential since available data on pregnancies in patients with BH4 deficiencies is limited.

Cerebrospinal fluid synaptic proteins as useful biomarkers in tyrosine hydroxylase deficiency.

Tyrosine hydroxylase (TH) deficiency is an inborn error of dopamine biosynthesis and a cause of early parkinsonism. Two clinical phenotypes have been described. Type "B": early onset severe encephalopathy; type "A": later onset, less severe and better response to L-dopa. We aimed to study the expression of several key dopaminergic and gabaergic synaptic proteins in the cerebrospinal fluid (CSF) of a series of patients with TH deficiency and their possible relation with the clinical phenotype and response to L-DOPA. Dopamine transporter (DAT), D2-receptor and vesicular monoamine transporter (VMAT2) were measured in the CSF of 10 subjects with TH deficiency by Western blot analysis. In 3 patients, data of pre- and post-treatment with L-DOPA were available, and in one of them, GABA vesicular transporter was determined. Results were compared to an age-matched control population. The concentration of D2-receptors in CSF was significantly higher in patients with TH deficiency than in controls. Similarly, DAT and vesicular monoamine transporter type 2 were up-regulated. Studies performed before L-DOPA, and on L-DOPA therapy showed a paradoxical response with D2 receptor expression increase as L-Dopa doses and homovanillic concentration gradually raised in a B phenotype patient. The opposite results were found in two patients with A phenotype. However, this is a very small sample, and further studies are needed to conclude robust differences between phenotypes. Synaptic proteins are detectable in the CSF and their quantification can be useful for understanding the pathophysiology of neurotransmitter defects and potentially to adjust and personalize treatments in the future.

High frequency of GJA12/GJC2 mutations in Turkish patients with Pelizaeus-Merzbacher disease.

Pelizaeus-Merzbacher disease is an early onset dysmyelinating leukodystrophy. About 80% of PMD cases have been associated with duplications and mutations of the proteolipid protein 1 (PLP1) gene. Pelizaeus-Merzbacher-like disease is a genetically heterogeneous autosomal recessive disease and rarely caused by mutations in gap junction protein α12 (GJA12/GJC2) gene. The molecular basis of the disease was investigated in a cohort of 19 Turkish families. This study identified novel chromosomal rearrangements proximal and distal to, and exclusive of the PLP1 gene, showed equal frequencies of PLP1 and GJA12/GJC2 mutations at least in our cohort, and suggested further genetic heterogeneity.

Clinical characteristics of pediatric-onset neuro-Behçet disease.

OBJECTIVES: Neurologic involvement in the pediatric population with Behçet disease (BD) is limited to case reports. The aim of this study is to examine the frequency and type of neurologic involvement in pediatric patients with BD. METHODS: Medical records of 728 patients with a diagnosis of neuro-BD (NBD) of 2 large BD cohorts followed in Istanbul University were included in the study. Patients with an onset of both systemic and neurologic symptoms at or before age 16 (pediatric neuro-BD) were identified. Demographic and clinical characteristics of pediatric patients with NBD were compared with adult patients with NBD. RESULTS: There were 26 cases with pediatric BD (3.6%) and 702 (96.4%) adult-onset patients. Gender ratio was equal in the general pediatric BD cohort, whereas male/female ratio was 5.5/1 in pediatric NBD cases. Mean age at BD onset and neurologic involvement onset were 13.0 ± 3.0 and 13.5 ± 2.4, respectively, and in the adult population mean age at onset of BD was 26.7 ± 8.0 and neurologic involvement occurred a mean of 5.3 ± 4.5 years later. Clinical and MRI evaluation revealed that 3 children had CNS parenchymal involvement and 23 had dural venous sinus thrombosis (88.5%). We observed parenchymal involvement in 74.8% of the adults, contrary to the low 17.2% of cases with venous sinus thrombosis. CONCLUSIONS: Pediatric NBD comprises 3.6% of our whole NBD cohort, with a male predominance, mainly in the form of dural venous sinus thrombosis, whereas in the adult NBD population the dominant form of neurologic involvement is parenchymal, suggesting that the pathogenesis of NBD may be different according to the age at disease onset.

Analgesic effects of skin-to-skin contact and breastfeeding in procedural pain in healthy term neonates.

OBJECTIVES: The effectiveness of skin-to-skin contact to decrease pain from heel-lancing in healthy term neonates and whether breastfeeding in addition to skin-to-skin contact provided a more effective analgesia than skin-to-skin contact alone were investigated. METHODS: A randomised, controlled trial was conducted in 107 neonates undergoing heel-lance. Infants were randomly assigned to three groups: (i) being breastfed with skin-to-skin contact (group 1, n=35), (ii) being held in their mother's arms with skin-to-skin contact but no breastfeeding (group 2, n=36), or (iii) lying on the table before, during and after painful stimulus (group 3, n=36). Physiological responses to pain were measured by heart rate and oxygen saturation changes and behavioural responses were measured by duration of crying and grimacing. RESULTS: Infants had a mean (SD) birthweight of 3355 (270) g and gestational age of 39.5 (0.6) weeks; at the time of the procedure, mean (SD) postnatal age was 33.1 (5) hours. There was no significant difference between the groups in clinical characteristics and time spent squeezing the heel. Heart rate, oxygen saturation changes and length of crying were significantly reduced in groups 1 and 2 compared with group 3 (p<0.001). No difference was found between group 1 and group 2. Grimacing was less in group 2 than in group 3 (p<0.001). CONCLUSIONS: In healthy term neonates, skin-to-skin contact with the mother and breastfeeding with skin-to-skin contact reduce both physiological and behavioural pain response. Breastfeeding in the 1st 2 postnatal days with skin-to-skin contact did not increase the analgesic effect of skin-to-skin contact alone.

Two cases with progressive cystic leukoencephalopathy.

Leukoencephalopathies with cystic changes in the white matter on magnetic resonance imaging are aetiologically heterogeneous neurological disorders seen in children. A group of leukoencephalopathies characterised by white matter lesions progressing to multifocal cystic degeneration has been reported in various disorders, including mitochondrial enzyme deficiencies, leukodystrophies, and infectious processes. We report two patients with leukoencephalopathy showing progressive cystic changes on serial MRI, and magnetic resonance spectroscopy resembling progressive cavitating leukoencephalopathy.

High interleukin-10 production is associated with anti-acetylcholine receptor antibody production and treatment response in juvenile myasthenia gravis.

To investigate the significance of humoral immunological factors in juvenile myasthenia gravis (JMG) patients, 11 children with JMG (age of onset between 2 and 13 years) and 8 healthy controls were enrolled. Plasma IL-2, IL-10, IFN-gamma, TNF-alpha, complement factor C3, C4, and C1q levels were measured by ELISA. IL-2, IL-10, TNF-alpha, C3, and C4 levels were significantly elevated in the patient group. Moreover, plasma IL-10 levels were associated with the presence of anti-AChR antibody and response to treatment suggesting a critical role for IL-10 in JMG pathogenesis.

Non-progressive congenital ataxia with cerebellar hypoplasia in three families.

AIM: Non-progressive ataxias with cerebellar hypoplasia are a rarely seen heterogeneous group of hereditary cerebellar ataxias. METHOD: Three sib pairs from three different families with this entity have been reviewed, and differential diagnosis has been discussed. RESULTS: In two of the families, the parents were consanguineous. Walking was delayed in all the children. Truncal and extremity ataxia were then noticed. Ataxia was severe in one child, moderate in two children, and mild in the remaining three. Neurological examination revealed horizontal, horizonto-rotatory and/or vertical nystagmus, variable degrees of mental retardation, and pyramidal signs besides truncal and extremity ataxia. In all the cases, cerebellar hemisphere and vermis hypoplasia were detected in MRI. During the follow-up period, a gradual clinical improvement was achieved in all the children. CONCLUSION: Inheritance should be considered as autosomal recessive in some of the non-progressive ataxic syndromes. Congenital non-progressive ataxias are still being investigated due to the rarity of large pedigrees for genetic studies. If further information on the aetiopathogenesis and clinical progression of childhood ataxias associated with cerebellar hypoplasia is to be acquired, a combined evaluation of metabolic screening, long-term follow-up and radiological analyses is essential.