Electro-clinical features in epileptic children with chromosome 15q duplication syndrome.

OBJECTIVE: We aimed to describe epilepsy and EEG patterns related to vigilance states and age, in chromosome15-long-arm-duplication-syndrome (dup15q) children with epilepsy, in both duplication types: interstitial (intdup15) and isodicentric (idic15). METHODS: Clinical data and 70 EEGs of 12 patients (5 intdup15, 7 idic15), followed from 4.5 m.o to 17y4m (median follow-up 8y3m), were retrospectively reviewed. EEGs were analyzed visually and using power spectrum analysis. RESULTS: Seventy video-EEGs were analyzed (1-16 per patient, median 6), follow-up lasting up to 8y10m (median 4y2m): 25 EEGs in intdup15 (8 m.o to 12y.o, median 4y6m) and 45 EEGs in idic15 (7 m.o to 12 y.o, median 15 m). Epilepsy: 6 West syndrome (WS) (2intdup15, 4idic15); 4 Lennox-Gastaut syndromes (LGS) (1 intdup15, 3 idic15), 2 evolving from WS; focal epilepsy (3 intdup15). In idic15, WS displayed additional myoclonic seizures (3), atypical (4) or no hypsarrhythmia (2) and posterior predominant spike and polyspike bursts (4). Beta-band rapid-rhythms (RR): present in 11 patients, power decreased during non-REM-sleep, localization shifted from diffuse to anterior, peak frequency increased with age. CONCLUSION: WS with peculiar electro-clinical features and LGS, along with beta-band RR decreasing in non-REM-sleep and shifting from diffuse to anterior localization with age are recognizable features pointing towards dup15q diagnosis in children with autism spectrum disorder and developmental delay. SIGNIFICANCE: This study describes electroclinical features in both interstitial and isodicentric duplications of chromosome 15q, in epileptic children, including some recent extensions regarding sleep features; and illustrates how the temporo-spatial organization of beta oscillations can be of significant help in directing towards dup15q diagnosis hypothesis.

Increased incidence of obstetric complications in women carrying mitochondrial DNA mutations: a retrospective cohort study in a single tertiary centre.

OBJECTIVE: To investigate the obstetric outcome of women carriers of the oxidative phosphorylation (OXPHOS) disorder mutation. DESIGN: A retrospective cohort study in a single tertiary centre. SETTING: A review of the obstetric history of women referred for prenatal screening of a mitochondrial disorder was performed. POPULATION: Women were divided into three groups: (1) women carrying mitochondrial DNA (mtDNA) mutations; (2) healthy women with a family history of mtDNA-related OXPHOS disorder; and (3) healthy women carrying heterozygote nuclear DNA mutations. METHODS: Obstetric history and pregnancy complications were evaluated separately in the three groups and compared with the control group. MAIN OUTCOME MEASURES PREGNANCY COMPLICATIONS. RESULTS: Seventy-five women were included with 287 cumulative pregnancies. Groups 1 and 3 had a significantly greater proportion of terminations of pregnancy (20 and 13% versus 0.8%, P < 0.001), and a lower percentage of live births (52 and 72% versus 87%, P = 0.001), compared with controls. Apart from this, the rate of obstetric complications in group 3 did not differ from the controls. The obstetric history of women in group 1 was marked by higher rates of early miscarriages (26 versus 11%, P = 0.004), gestational diabetes (14 versus 3%, P = 0.02), intrauterine growth restriction (IUGR, 10 versus 1%, P = 0.008), and postpartum haemorrhage than were reported for controls (12 versus 2%, P = 0.01). CONCLUSION: Women who are heteroplasmic for OXPHOS mutations have a higher incidence of pregnancy losses, gestational diabetes, IUGR, and post postpartum haemorrhage. TWEETABLE ABSTRACT: Women heteroplasmic for mitochondrial DNA mutations have a higher incidence of obstetric complications, compared with the control group.

Causes, diagnosis and therapy of common diseases in neonatal puppies in the first days of life: cornerstones of practical approach.

Neonatal diseases and losses are a common and often unavoidable problem within breeding kennels. Altogether, morbidity and mortality ranges, according to the literature, from 5 to 35%. Among non-infectious causes besides hypoxia during birth, hypothermia, hypoglycaemia and dehydration are mostly responsible for puppy diseases and losses. Approximately 90% of all deaths in hypoxaemic pups occur during the first 2 days. Of 183 pups with hypoxia, 63 died, 92.7% of them within 48 h after birth. Among infectious causes, bacterial infection is the most common cause of neonatal mortality. Escherichia coli, streptococci, staphylococci, Pseudomonas sp., Klebsiella sp., Enterobacter sp. and some other micro-organisms are regularly involved in neonatal infections. Post-mortem findings especially document E. coli, Staphylococcus sp. and Streptococcus sp. as responsible bacteria. The dam and the environment are suspected as sources of neonatal infections as it was shown by genetic relatedness of responsible bacterial strains isolated in both puppies and their dams. From a total of 517 puppies with bacterial infections, the treatment results documented that parenteral administration of amoxicillin/clavulanic acid in 308 neonates showed the best result. Diagnosis of diseases is often made difficult by the absence of variability in clinical signs contrary to adult dogs. Findings during a physical examination in pups differ from those in adults. Furthermore, treatment recommendations have to meet the special conditions in neonates concerning drug metabolism and excretion.

Brain imaging in mitochondrial respiratory chain deficiency: combination of brain MRI features as a useful tool for genotype/phenotype correlations.

Mitochondrial diseases are characterised by a broad clinical and genetic heterogeneity that makes diagnosis difficult. Owing to the wide pattern of symptoms in mitochondrial disorders and the constantly growing number of disease genes, their genetic diagnosis is difficult and genotype/phenotype correlations remain elusive. Brain MRI appears as a useful tool for genotype/phenotype correlations. Here, we summarise the various combinations of MRI lesions observed in the most frequent mitochondrial respiratory chain deficiencies so as to direct molecular genetic test in patients at risk of such diseases. We believe that the combination of brain MRI features is of value to support respiratory chain deficiency and direct molecular genetic tests.

[Aspect of brain MRI in mitochondrial respiratory chain deficiency. A diagnostic algorithm of the most common mitochondrial genetic mutations]. / Aspect en IRM cérébrale des maladies mitochondriales. Algorithme décisionnel des maladies mitochondriales les plus fréquentes.

Mitochondrial diseases are due to deficiency of the respiratory chain and are characterized by a broad clinical and genetic heterogeneity that makes diagnosis difficult. Some clinical presentations are highly suggestive of given gene mutations, allowing rapid genetic diagnosis. However, owing to the wide pattern of symptoms in mitochondrial disorders and the constantly growing number of disease genes, their genetic diagnosis is frequently difficult and genotype/phenotype correlations remain elusive. For this reason, brain MRI appears as a useful tool for genotype/phenotype correlations. Here, we report the most frequent neuroradiological signs in mitochondrial respiratory chain deficiency and we propose a diagnostic algorithm based on neuroimaging features, so as to direct molecular genetic tests in patients at risk of mitochondrial respiratory chain deficiency. This algorithm is based on the careful analysis of five areas on brain MRI: (1) basal ganglia (hyperintensities on T2 or calcifications); (2) cerebellum (hyperintensities on T2 or atrophy); (3) brainstem (hyperintensities on T2 or atrophy); (4) white matter (leukoencephalopathy); (5) cortex (sub-tentorial atrophy); (6) stroke-like episodes. We believe that the combination of brain MRI features is of value to support respiratory chain deficiency and direct molecular genetic tests.

A novel mutation in STXBP1 causing epileptic encephalopathy (late onset infantile spasms) with partial respiratory chain complex IV deficiency.

STXBP1 (MUNC18.1), encoding syntaxin binding protein 1, has been reported in Ohtahara syndrome, a rare epileptic encephalopathy with suppression burst pattern on EEG, in patients with infantile spasms and in a few patients with nonsyndromic mental retardation without epilepsy. We report a patient who presented late onset infantile spasms. Epilepsy was controlled but the patient developed severe mental delay. A first diagnosis of mitochondrial disease was based on clinical presentation and on a partial deficit of respiratory chain complex IV, but molecular screening for mitochondrial genes was negative. The sequencing of STXBP1 gene found a de novo nonsense mutation (c.585C>G/p.Tyr195X). This observation widens the clinical spectrum linked to STXBP1 mutations with the description of a patient with late onset infantile spasms. It raises the question of the value of epilepsy genes screening in patients with uncertain, partial or unconfirmed mitochondrial dysfunction.

Phenotype and genotype in 101 males with X-linked creatine transporter deficiency.

BACKGROUND: Creatine transporter deficiency is a monogenic cause of X-linked intellectual disability. Since its first description in 2001 several case reports have been published but an overview of phenotype, genotype and phenotype--genotype correlation has been lacking. METHODS: We performed a retrospective study of clinical, biochemical and molecular genetic data of 101 males with X-linked creatine transporter deficiency from 85 families with a pathogenic mutation in the creatine transporter gene (SLC6A8). RESULTS AND CONCLUSIONS: Most patients developed moderate to severe intellectual disability; mild intellectual disability was rare in adult patients. Speech language development was especially delayed but almost a third of the patients were able to speak in sentences. Besides behavioural problems and seizures, mild to moderate motor dysfunction, including extrapyramidal movement abnormalities, and gastrointestinal problems were frequent clinical features. Urinary creatine to creatinine ratio proved to be a reliable screening method besides MR spectroscopy, molecular genetic testing and creatine uptake studies, allowing definition of diagnostic guidelines. A third of patients had a de novo mutation in the SLC6A8 gene. Mothers with an affected son with a de novo mutation should be counselled about a recurrence risk in further pregnancies due to the possibility of low level somatic or germline mosaicism. Missense mutations with residual activity might be associated with a milder phenotype and large deletions extending beyond the 3' end of the SLC6A8 gene with a more severe phenotype. Evaluation of the biochemical phenotype revealed unexpected high creatine levels in cerebrospinal fluid suggesting that the brain is able to synthesise creatine and that the cerebral creatine deficiency is caused by a defect in the reuptake of creatine within the neurones.

Clinical and Genetic Study of Algerian Patients with Spinal Muscular Atrophy.

Spinal muscular atrophy (SMA) is the second most common lethal autosomal recessive disorder. It is divided into the acute Werdnig-Hoffmann disease (type I), the intermediate form (type II), the Kugelberg-Welander disease (type III), and the adult form (type IV). The gene involved in all four forms of SMA, the so-called survival motor neuron (SMN) gene, is duplicated, with a telomeric (tel SMN or SMN1) and a centromeric copy (cent SMN or SMN2). SMN1 is homozygously deleted in over 95% of SMA patients. Another candidate gene in SMA is the neuronal apoptosis inhibitory protein (NAIP) gene; it shows homozygous deletions in 45-67% of type I and 20-42% of type II/type III patients. Here we studied the SMN and NAIP genes in 92 Algerian SMA patients (20 type I, 16 type II, 53 type III, and 3 type IV) from 57 unrelated families, using a semiquantitative PCR approach. Homozygous deletions of SMN1 exons 7 and/or 8 were found in 75% of the families. Deletions of exon 4 and/or 5 of the NAIP gene were found in around 25%. Conversely, the quantitative analysis of SMN2 copies showed a significant correlation between SMN2 copy number and the type of SMA.

Monozygotic twins discordant for submicroscopic chromosomal anomalies in 2p25.3 region detected by array CGH.

Although discordant phenotypes in monozygotic twins with developmental disorder are not an exception, underlying genetic discordance is rarely reported. Here, we report on the clinical and cytogenetic details of 4-year-old female monozygotic twins with discordant phenotypes. Twin 1 exhibited global developmental delay, overweight and hyperactivity. Twin 2 had an autistic spectrum disorder. Molecular karyotyping in twin 1 identified a 2p25.3 deletion, further confirmed by Fluorescence in situ hybridization (FISH) analysis on leukocytes. Interestingly, array comparative genomic hybridization was normal in twin 2 but FISH analysis using the same probe as twin 1 showed mosaicism with one-third of cells with a 2p25.3 deletion, one-third of cells with a 2p25.3 duplication, and one-third of normal cells. Genotyping with microsatellite markers confirmed the monozygosity of the twins. We propose that the chromosome imbalance may be due to a mitotic non-allelic recombination occurring during blastomeric divisions of a normal zygote. Such event will result in three distinct cell populations, whose proportion in each embryo formed after separation from the zygote may differ, leading to discordant chromosomal anomalies between twins. We also discuss that the MYTL1L and the SNTG2 genes within the reported region could probably relate to the phenotypic discordance of the monozygotic twins.

A constant and similar assembly defect of mitochondrial respiratory chain complex I allows rapid identification of NDUFS4 mutations in patients with Leigh syndrome.

Isolated complex I deficiency is a frequent cause of respiratory chain defects in childhood. In this study, we report our systematic approach with blue native PAGE (BN-PAGE) to study mitochondrial respiratory chain assembly in skin fibroblasts from patients with Leigh syndrome and CI deficiency. We describe five new NDUFS4 patients with a similar and constant abnormal BN-PAGE profile and present a meta-analysis of the literature. All NDUFS4 mutations that have been tested with BN-PAGE result in a constant and similar abnormal assembly profile with a complete loss of the fully assembled complex I usually due to a truncated protein and the loss of its canonical cAMP dependent protein kinase phosphorylation consensus site. We also report the association of abnormal brain MRI images with this characteristic BN-PAGE profile as the hallmarks of NDUFS4 mutations and the first founder NDUFS4 mutations in the North-African population.

A novel microdeletion syndrome at 3q13.31 characterised by developmental delay, postnatal overgrowth, hypoplastic male genitals, and characteristic facial features.

BACKGROUND: Congenital deletions affecting 3q11q23 have rarely been reported and only five cases have been molecularly characterised. Genotype-phenotype correlation has been hampered by the variable sizes and breakpoints of the deletions. In this study, 14 novel patients with deletions in 3q11q23 were investigated and compared with 13 previously reported patients. METHODS: Clinical data were collected from 14 novel patients that had been investigated by high resolution microarray techniques. Molecular investigation and updated clinical information of one cytogenetically previously reported patient were also included. RESULTS: The molecular investigation identified deletions in the region 3q12.3q21.3 with different boundaries and variable sizes. The smallest studied deletion was 580 kb, located in 3q13.31. Genotype-phenotype comparison in 24 patients sharing this shortest region of overlapping deletion revealed several common major characteristics including significant developmental delay, muscular hypotonia, a high arched palate, and recognisable facial features including a short philtrum and protruding lips. Abnormal genitalia were found in the majority of males, several having micropenis. Finally, a postnatal growth pattern above the mean was apparent. The 580 kb deleted region includes five RefSeq genes and two of them are strong candidate genes for the developmental delay: DRD3 and ZBTB20. CONCLUSION: A newly recognised 3q13.31 microdeletion syndrome is delineated which is of diagnostic and prognostic value. Furthermore, two genes are suggested to be responsible for the main phenotype.

Kinetic analyses guide the therapeutic decision in a novel form of moderate aromatic Acid decarboxylase deficiency.

BACKGROUND: Aromatic amino acid decarboxylase (AADC) deficiency is a rare autosomal recessive disorder resulting in a combined dopamine and serotonin deficiency. About 50% of the cases set in the neonatal period. Here, we report an atypical clinical presentation with moderate symptoms. PATIENT: At 10months old, the patient presented paroxysmal eye movements without seizures, and feeding difficulties which were attributed to gastroesophageal reflux. She was investigated at the age of 7years, because of orofacial dyspraxia, hypomimie, axial hypotonia and focal segmental dystonia, bilateral ptosis, without evidence for cognitive impairment. RESULTS: HVA [110nM; (reference value (rv): 202-596)] and HIAA (12nM; rv: 87-366) decreased, OMD (520nM; rv: 5-60) and 5-HTP (56nM; rv: 2-16) increased in CSF. We confirmed the diagnosis of AADC deficiency because the activity in plasma was low: 4pmol/min/ml; rv: 16-137. The kinetic analysis revealed a sixfold increase in the apparent affinity for L-dopa (4.26mM; control=0.71), but the V (max) was unchanged (37.5pmol dopamine/min/ml; control=39.1), suggesting a modification in the substrate binding-site. Molecular analysis revealed two heterozygous mutations in the DDC gene: c1040G > A; pR347Q already described, and a novel mutation c478C > T, pR160W. CONCLUSION: (1) CSF neurotransmitters metabolites suggested a moderate AADC deficiency; (2) The initial velocity saturation curve for L-dopa displayed a cooperative ligand binding behavior, in keeping with the modifications of the three-dimensional structure, induced by the amino acid substitutions (3) The treatment combination of L-dopa with pyridoxine dramatically improved the quality of life, the fatigability, and the paroxysmal eye movements.

[Preimplantation diagnosis with HLA typing: birth of the first double hope child in France]. / Diagnostic préimplantatoire avec typage HLA : naissance du premier enfant du double espoir en France.

Preimplantation genetic diagnosis (PGD) is authorized in France since 1999. After 10 years, technical results are encouraging. With the development of new technologies, our team is able to diagnosis the large majority of chromosome translocations and 75 monogenic diseases. However, PGD remains limited because of the growing augmentation of demands causing an increasing delay for the first procedure of more than 18 months. Since 2006, 19 couples asked for a PGD with HLA typing. In January 2011, 11 couples have already been included in our PGD program. The birth of the first child after PGD with HLA typing offers new perspectives of treatment for these couples.

Comprehensive cDNA study and quantitative analysis of mutant HADHA and HADHB transcripts in a French cohort of 52 patients with mitochondrial trifunctional protein deficiency.

BACKGROUND: Deficiency of mitochondrial trifunctional protein (MTP) is caused by mutations in the HADHA and HADHB genes, which have been mostly delineated at the genomic DNA level and have not been always elucidated. AIM: To identify mutations in a French cohort of 52 MTP deficient patients and the susceptibility of mutations generating premature termination codons (PTCs) to the nonsense mRNA mediated decay (NMD). METHODS: Mutation screening in fibroblasts was performed at the cDNA level and real-time RT-PCR was used to compare the levels of the different PTC-bearing mRNAs before and after a treatment of fibroblasts by emetine, a translation inhibitor. RESULTS: A mutation detection rate of 100% was achieved. A total of 22 novel mutations were identified, including a large-sized genomic deletion in HADHB gene. A high proportion of all identified mutations were non-sense, frameshift and splicing mutations, generating (PTCs), distributed essentially on HADHA coding regions. We could demonstrate that the majority of mutations resulting in PTCs conform to the established rules governing the susceptibility to NMD. CONCLUSION: Our results emphasize the value of cDNA analysis in the characterization of HADHA and HADHB mutations and further strengthen the model of haploinsufficiency as a major pathomechanism in MTP defects.

Normal oxidative phosphorylation in intestinal smooth muscle of childhood chronic intestinal pseudo-obstruction.

BACKGROUND: Chronic intestinal pseudo-obstruction (CIPO) is a severe disease of the digestive tract motility. In pediatric population, CIPO remains of unknown origin for most patients. Chronic intestinal pseudo-obstruction is also a common feature in the course of mitochondrial oxidative phosphorylation disorders related for some patients to mutations in TYMP, POLG1, mtDNA tRNA(leu(UUR)) or tRNA(lys) genes. We hypothesized that CIPOs could be the presenting symptom of respiratory chain enzyme deficiency and thus we investigated oxidative phosphorylation in small bowel and/or colon smooth muscle of primary CIPO children. METHODS: We studied eight children with CIPO and 12 pediatric controls. We collected clinical, radiological and pathological data and measured respiratory chain enzymatic activity in isolated smooth muscle of the small bowel and/or the colon. We also sequenced TYMP, POLG, mtDNA tRNA(leu(UUR)) and tRNA(lys) genes. KEY RESULTS: Neither pathological nor radiological data were in favor of a mitochondrial dysfunction. No respiratory chain enzyme deficiency was detected in CIPO children. In myogenic CIPO, respiratory enzymes and citrate synthase activities were increased in small bowel and/or colon whereas no abnormality was noted in neurogenic and unclassified CIPO. Levels of enzyme activities were higher in control small bowel than in control colon muscle. Sequencing of TYMP, POLG, mtDNA tRNA(leu(UUR)) and tRNA(lys) genes and POLG gene did not reveal mutation for any of the patients. CONCLUSIONS & INFERENCES: The normal enzymatic activities as the lack of radiological and genetic abnormalities indicate that, at variance with adult patients, oxidative phosphorylation deficiency is not a common cause of childhood CIPO.

A common pattern of brain MRI imaging in mitochondrial diseases with complex I deficiency.

OBJECTIVE: To identify a consistent pattern of brain MRI imaging in primary complex I deficiency. Complex I deficiency, a major cause of respiratory chain dysfunction, accounts for various clinical presentations, including Leigh syndrome. Human complex I comprises seven core subunits encoded by mitochondrial DNA (mtDNA) and 38 core subunits encoded by nuclear DNA (nDNA). Moreover, its assembly requires six known and many unknown assembly factors. To date, no correlation between genotypes and brain MRI phenotypes has been found in complex I deficiencies. DESIGN AND SUBJECTS: The brain MRIs of 30 patients carrying known mutation(s) in genes involved in complex I were retrospectively collected and compared with the brain MRIs of 11 patients carrying known mutations in genes involved in the pyruvate dehydrogenase (PDH) complex as well as 10 patients with MT-TL1 mutations. RESULTS: All complex I deficient patients showed bilateral brainstem lesions (30/30) and 77% (23/30) showed anomalies of the putamen. Supratentorial stroke-like lesions were only observed in complex I deficient patients carrying mtDNA mutations (8/19) and necrotising leucoencephalopathy in patients with nDNA mutations (4/5). Conversely, the isolated stroke-like images observed in patients with MT-TL1 mutations, or the corpus callosum malformations observed in PDH deficient patients, were never observed in complex I deficient patients. CONCLUSION: A common pattern of brain MRI imaging was identified with abnormal signal intensities in brainstem and subtentorial nuclei with lactate peak as a clue of complex I deficiency. Combining clinico-biochemical data with brain imaging may therefore help orient genetic studies in complex I deficiency.