Deciphering the natural history of SCA7 in children.

BACKGROUND AND PURPOSE: Childhood-onset autosomal dominant cerebellar ataxia type 7 (SCA7) is a severe disease which leads to premature loss of ambulation and death. Early diagnosis of SCA7 is of major importance for genetic counselling and still relies on specific genetic testing, driven by clinical expertise. However, the precise phenotype and natural history of paediatric SCA7 has not yet been fully described. Our aims were to describe the natural history of SCA7 in a large multicentric series of children of all ages, and to find correlates to variables defining this natural history. METHODS: We collected and analysed clinical data from 28 children with proven SCA7. All had clinical manifestations of SCA7 and either a definite number of CAG repeats in ATXN7 or a long expansion > 100 CAG. RESULTS: We identified four clinical presentation patterns related to age at onset. Children of all age groups had cerebellar atrophy and retinal dystrophy. Our data, combined with those in the literature, suggest that definite ranges of CAG repeats determine paediatric SCA7 subtypes. The number of CAG repeats inversely correlated to all variables of the natural history. Age at gait ataxia onset correlated accurately to age at loss of walking ability and to age at death. CONCLUSION: SCA7 in children has four presentation patterns that are roughly correlated to the number of CAG repeats. Our depiction of the natural history of SCA7 in children may help in monitoring the effect of future therapeutic trials.

A new highly penetrant form of obesity due to deletions on chromosome 16p11.2.

Obesity has become a major worldwide challenge to public health, owing to an interaction between the Western 'obesogenic' environment and a strong genetic contribution. Recent extensive genome-wide association studies (GWASs) have identified numerous single nucleotide polymorphisms associated with obesity, but these loci together account for only a small fraction of the known heritable component. Thus, the 'common disease, common variant' hypothesis is increasingly coming under challenge. Here we report a highly penetrant form of obesity, initially observed in 31 subjects who were heterozygous for deletions of at least 593 kilobases at 16p11.2 and whose ascertainment included cognitive deficits. Nineteen similar deletions were identified from GWAS data in 16,053 individuals from eight European cohorts. These deletions were absent from healthy non-obese controls and accounted for 0.7% of our morbid obesity cases (body mass index (BMI) >or= 40 kg m(-2) or BMI standard deviation score >or= 4; P = 6.4 x 10(-8), odds ratio 43.0), demonstrating the potential importance in common disease of rare variants with strong effects. This highlights a promising strategy for identifying missing heritability in obesity and other complex traits: cohorts with extreme phenotypes are likely to be enriched for rare variants, thereby improving power for their discovery. Subsequent analysis of the loci so identified may well reveal additional rare variants that further contribute to the missing heritability, as recently reported for SIM1 (ref. 3). The most productive approach may therefore be to combine the 'power of the extreme' in small, well-phenotyped cohorts, with targeted follow-up in case-control and population cohorts.

Unusual cutaneous features associated with a heterozygous gain-of-function mutation in IFIH1: overlap between Aicardi-Goutières and Singleton-Merten syndromes.

Cutaneous lesions described as chilblain lupus occur in the context of familial chilblain lupus or Aicardi-Goutières syndrome. To date, seven genes related to Aicardi-Goutières syndrome have been described. The most recently described encodes the cytosolic double-stranded RNA receptor IFIH1 (also known as MDA5), a key component of the antiviral type I interferon-mediated innate immune response. Enhanced type I interferon signalling secondary to gain-of-function mutations in IFIH1 can result in a range of neuroinflammatory phenotypes including classical Aicardi-Goutières syndrome. It is of note that none of the patients with a neurological phenotype so far described with mutations in this gene was reported to demonstrate cutaneous involvement. We present a family segregating a heterozygous pathogenic mutation in IFIH1 showing dermatological involvement as a prominent feature, variably associated with neurological disturbance and premature tooth loss. All three affected individuals exhibited increased expression of interferon-stimulated genes in whole blood, and the mutant protein resulted in enhanced interferon signalling in vitro, both in the basal state and following ligand stimulation. Our results further extend the phenotypic spectrum associated with mutations in IFIH1, indicating that the disease can be confined predominantly to the skin, while also highlighting phenotypic overlap with both Aicardi-Goutières syndrome and Singleton-Merten syndrome.

Endocrine disorders in Woodhouse-Sakati syndrome: a systematic review of the literature.

First described in 1983, Woodhouse-Sakati syndrome (WSS) is a rare autosomal recessive genetic disorder that leads to a spectrum of hypogonadal symptoms in adolescence. The responsible gene, DCAF17 located on chromosome 2q31.1, was discovered in 2008 and to date nine mutations have been reported in the literature. The aim of the study was to review WSS descriptively in the light of new case reports with focus on endocrine features. Phenotypic description of three patients (two females, one male) with WSS followed in the Endocrinology Department of the University Hospital of Nancy, France, and exhaustive review of the literature using the PUBMED database were performed. Of 72 patients from 29 families with documented WSS who were identified, 39 had undergone genetic testing. WSS was invariably associated with hypogonadism, decreased IGF1 and frontotemporal alopecia starting in childhood. In addition to this triad, some patients exhibited intellectual disabilities of varying severity (87 %), bilateral deafness (76 %), cervicofacial dystonia and limb pain (42 % of cases, rising to 89 % after 25 years) and diabetes (66 %, rising to 96 % after 25 years). The pathophysiology of WSS remains unclear.

Undiagnosed phenylketonuria in parents of phenylketonuric patients, is it worthwhile to be checked?

In our phenylketonuria (PKU) cohort of 120 patients, we uncovered a couple of cases of undiagnosed mild phenylketonuria (mPKU)/hyperphenylalaninemia (mHPA) in maternal parents of the PKU cohort. This finding prompted us to evaluate the risk of either mild phenylketonuria or mild hyperphenylalaninemia in the parent population whose children were diagnosed with hyperphenylalaninemia (HPA). Taking into account the phenylalanine hydroxylase (PAH) mutation carrier frequency and the PAH mild mutation rate, we estimated that the prevalence of the parental mPKU/mHPA varied widely, from 1/74 in Turkey to 1/708 in Lithuania. The benefits of the parental detection procedure described here are the prevention of further maternal PKU syndrome, the follow-up of the newly detected patients and the accuracy of the genetic counseling provided to these families. This very simple procedure should be incorporated into neonatal PKU management of the hospitals in countries where a routine systematic neonatal screening is operational.

Systematic molecular and cytogenetic screening of 100 patients with marfanoid syndromes and intellectual disability.

The association of marfanoid habitus (MH) and intellectual disability (ID) has been reported in the literature, with overlapping presentations and genetic heterogeneity. A hundred patients (71 males and 29 females) with a MH and ID were recruited. Custom-designed 244K array-CGH (Agilent®; Agilent Technologies Inc., Santa Clara, CA) and MED12, ZDHHC9, UPF3B, FBN1, TGFBR1 and TGFBR2 sequencing analyses were performed. Eighty patients could be classified as isolated MH and ID: 12 chromosomal imbalances, 1 FBN1 mutation and 1 possibly pathogenic MED12 mutation were found (17%). Twenty patients could be classified as ID with other extra-skeletal features of the Marfan syndrome (MFS) spectrum: 4 pathogenic FBN1 mutations and 4 chromosomal imbalances were found (2 patients with both FBN1 mutation and chromosomal rearrangement) (29%). These results suggest either that there are more loci with genes yet to be discovered or that MH can also be a relatively non-specific feature of patients with ID. The search for aortic complications is mandatory even if MH is associated with ID since FBN1 mutations or rearrangements were found in some patients. The excess of males is in favour of the involvement of other X-linked genes. Although it was impossible to make a diagnosis in 80% of patients, these results will improve genetic counselling in families.

Maternal opioid addiction: A potential cause of elevated 17-OH progesterone in neonatal screening.

BACKGROUND: Congenital adrenal hyperplasia (CAH) is a disease that is part of neonatal screening. There are many causes of false-positive results on neonatal screening, and maternal opioid consumption during pregnancy is suspected to increase 17-hydroxyprogesterone (17-OHP) levels at birth. The aim of this study was to determine the effect of maternal drug consumption on 17-OHP values on neonatal screening. MATERIAL AND METHODS: We studied 17-OHP levels of term newborns with reported maternal drug consumption born at the Maternity Hospital of Nancy between 2002 and 2018. These infants were matched with newborns of mothers without drug addiction. The 17-OHP levels, withdrawal syndromes, birth parameters, and maternal characteristics were compared between the two groups. RESULTS: The study included 241 patients (121 in the drug-exposed group, 120 in the control group). The mean 17-OHP levels in newborns of mothers with substance addiction were 9.83 nmol/L compared to 4.90 nmol/L (p=0.0001) in the control group. Newborns exposed to drugs were smaller (p=0.0001), lighter (p=0.0001), had smaller head circumference (p=0.0001), and had lower Apgar scores (p=0.004 at 1 min and p=0.0001 at 5 min). The 17-OHP level did not differ in cases of withdrawal syndrome in drug-exposed newborn (p=0.911). CONCLUSION: A significant increase in 17-OHP levels was observed in newborns exposed to drugs, with no influence of withdrawal syndrome on 17-OHP levels. Maternal substance addiction may be associated with moderately increased 17-OHP levels during neonatal screening.

What do French patients and geneticists think about prenatal and preimplantation diagnoses in Marfan syndrome?

OBJECTIVES: Marfan syndrome (MFS) is an autosomal dominant connective tissue disorder with manifestations mainly involving the skeletal, ocular, and cardiovascular systems. The phenotypic variability observed in MFS makes genetic counselling difficult. Prenatal diagnosis (PND) and preimplantation genetic diagnosis are technically feasible when a causal mutation is identified, but both raise many ethical questions in this condition. Little is known about opinions and practices in such reproductive issues in MFS. The goal of this study was to report on patients' points of view and geneticists' standard practices. METHODS: Two different questionnaires were produced. RESULTS: Fifty geneticists filled in the questionnaire. Twenty-two per cent thought that PND was acceptable, 72% debatable and 6% not acceptable. Preimplantation genetic diagnosis was more often reported acceptable (34% of answers). Results varied according to the physician's experience with the disease. Fifty-four answers were collected for patients' questionnaires. Most of them (74%) were favourable to the development of prenatal testing, and believed that the choice should be given to parents. However, only a minority would opt for prenatal diagnosis for themselves. CONCLUSION: This study showed that the majority of patients were in favour of PND and that opinions among practitioners varied widely, but that overall, practitioners favoured a systematic multidisciplinary evaluation of the couple's request.

Molecular analysis of pericentrin gene (PCNT) in a series of 24 Seckel/microcephalic osteodysplastic primordial dwarfism type II (MOPD II) families.

Microcephalic osteodysplastic primordial dwarfism type II (MOPD II, MIM 210720) and Seckel syndrome (SCKL, MIM 210600) belong to the primordial dwarfism group characterised by intrauterine growth retardation, severe proportionate short stature, and pronounced microcephaly. MOPD II is distinct from SCKL by more severe growth retardation, radiological abnormalities, and absent or mild mental retardation. Seckel syndrome is associated with defective ATR dependent DNA damage signalling. In 2008, loss-of-function mutations in the pericentrin gene (PCNT) have been identified in 28 patients, including 3 SCKL and 25 MOPDII cases. This gene encodes a centrosomal protein which plays a key role in the organisation of mitotic spindles. The aim of this study was to analyse PCNT in a large series of SCKL-MOPD II cases to further define the clinical spectrum associated with PCNT mutations. Among 18 consanguineous families (13 SCKL and 5 MOPDII) and 6 isolated cases (3 SCKL and 3 MOPD II), 13 distinct mutations were identified in 5/16 SCKL and 8/8 MOPDII including five stop mutations, five frameshift mutations, two splice site mutations, and one apparent missense mutation affecting the last base of exon 19. Moreover, we demonstrated that this latter mutation leads to an abnormal splicing with a predicted premature termination of translation. The clinical analysis of the 5 SCKL cases with PCNT mutations showed that they all presented minor skeletal changes and clinical features compatible with MOPDII diagnosis. It is therefore concluded that, despite variable severity, MOPDII is a genetically homogeneous condition due to loss-of-function of pericentrin.

Microdeletion at chromosome 4q21 defines a new emerging syndrome with marked growth restriction, mental retardation and absent or severely delayed speech.

BACKGROUND Genome-wide screening of large patient cohorts with mental retardation using microarray-based comparative genomic hybridisation (array-CGH) has recently led to identification several novel microdeletion and microduplication syndromes. METHODS Owing to the national array-CGH network funded by the French Ministry of Health, shared information about patients with rare disease helped to define critical intervals and evaluate their gene content, and finally determine the phenotypic consequences of genomic array findings. RESULTS In this study, nine unrelated patients with overlapping de novo interstitial microdeletions involving 4q21 are reported. Several major features are common to all patients, including neonatal muscular hypotonia, severe psychomotor retardation, marked progressive growth restriction, distinctive facial features and absent or severely delayed speech. The boundaries and the sizes of the nine deletions are different, but an overlapping region of 1.37 Mb is defined; this region contains five RefSeq genes: PRKG2, RASGEF1B, HNRNPD, HNRPDL and ENOPH1. DISCUSSION Adding new individuals with similar clinical features and 4q21 deletion allowed us to reduce the critical genomic region encompassing two genes, PRKG2 and RASGEF1B. PRKG2 encodes cGMP-dependent protein kinase type II, which is expressed in brain and in cartilage. Information from genetically modified animal models is pertinent to the clinical phenotype. RASGEF1B is a guanine nucleotide exchange factor for Ras family proteins, and several members have been reported as key regulators of actin and microtubule dynamics during both dendrite and spine structural plasticity. CONCLUSION Clinical and molecular delineation of 4q21 deletion supports a novel microdeletion syndrome and suggests a major contribution of PRKG2 and RASGEF1B haploinsufficiency to the core phenotype.

Aberrant GRIA3 transcripts with multi-exon duplications in a family with X-linked mental retardation.

Investigation of chromosomal rearrangements in patients with mental retardation (MR) is particularly informative in the search for novel genes involved in MR. We report on a family with a genomic duplication at Xq25 identified by oligo array-CGH. Further characterization showed a partial tandem duplication of GRIA3 extending from exon 1 to exon 12. This duplication is present in two brothers with MR and on one allele in their sister with normal phenotype and completely skewed X-chromosome inactivation. The duplication is inherited from the mother, whose cognitive level is low and X-chromosome inactivation is random. This is the second family with partial duplication of GRIA3 associated with MR. GRIA3 expression studies in our case demonstrated a new mechanism for GRIA3 dysfunction with the presence of aberrant GRIA3 transcripts carrying multi-exon duplications leading to a frameshift. Our study gives additional support to the implication of GRIA3 in X-linked MR.

Confirmation of TFAP2A gene involvement in branchio-oculo-facial syndrome (BOFS) and report of temporal bone anomalies.

Branchio-oculo-facial syndrome (BOFS) is an autosomal-dominant condition characterized by three main features, respectively: branchial defects, ocular anomalies, and craniofacial defects including cleft lip and/or palate (CL/P). We report on one family with three affected, and two sporadic cases that have been found to carry missense mutations in the newly reported BOFS gene: TFAP2A. This report confirms the involvement of this transcription factor in this developmental syndrome with clinical variability. Moreover, we present CT scan temporal bone anomalies in the familial cases, related to branchial arch defects, highlighting the importance of radiological investigations for differential diagnosis.

The practice of physical and sporting activity in teenagers with idiopathic scoliosis is related to the curve type.

Idiopathic scoliosis (IS) is correlated with a muscular disequilibrium of the spine and an alteration of balance control, efficient performance of the latter being necessary for physical and sporting activities (PSA). However, the type of the IS curve has different effects on muscle and on balance control according to the primary curve location. This study aimed to determine the relationships between IS type and PSA practice. One hundred and sixty-nine girl adolescents with IS [double major curve (DMC) scoliosis: n=74; single major curve (SMC) scoliosis: n=95] and 100 age-matched control girl adolescents completed an epidemiological questionnaire informing on curricular and extracurricular PSA. Adolescents with DMC scoliosis practised more PSA than those with SMC scoliosis. Moreover, among all PSA referenced, gymnastic activities are the most practiced PSA both in IS teenagers, whatever the curve type, and in controls. Besides, teenagers practising gymnastics were more numerous in those with DMC scoliosis than those with SMC scoliosis and controls. The highest proportion of adolescents with DMC scoliosis practising PSA, especially gymnastics, could be linked to the fact that they are less subject to scoliosis-related biomechanical repercussions leading to a better balance control, which is essential in these PSA.

[Hypercalcemia revealing iatrogenic hypervitaminosis A in a child with autistic troubles]. / Hypercalcémie révélant une hypervitaminose A iatrogène chez un enfant atteint de troubles autistiques.

UNLABELLED: Hypervitaminosis A is an unusual cause of infant hypercalcemia. The way it occurs can be very surprising, as one can notice from the following case report. CASE REPORTS: A three-year-old boy, presenting important behavioral disorders, was hospitalized because of a deterioration of his general state of health associated with vomiting, cephalgias, fever and cutaneous abnormalities. A 168 mg/L hypercalcemia was found. The only etiology is a deviant consumption of vitamin A within the framework of an "autistic diet": 100000 UI/d during three months, and then 150000 UI/d the three following months. Intoxication was confirmed by the increased vitamin A plasmatic level, and vitamin A/RBP molar ratio and by the presence of plasmatic retinyl palmitate. An emergency treatment by rehydration, biphosphonates and furosemide led to effective calcemia normalization. CONCLUSION: In the case of nonobvious causes of hypercalcemia, a thorough cross-examination must look for vitamin A intoxication. Our observation illustrates the danger of certain diets suggested for autistic children.

Mutational spectrum of COH1 and clinical heterogeneity in Cohen syndrome.

Cohen syndrome (CS) is an autosomal recessive disorder with variability in the clinical manifestations, characterised by mental retardation, postnatal microcephaly, facial dysmorphism, pigmentary retinopathy, myopia, and intermittent neutropenia. Mutations in the gene COH1 have been found in an ethnically diverse series of patients. Brief clinical descriptions of 24 patients with CS are provided. The patients were from 16 families of different ethnic backgrounds and between 2.5 and 60 years of age at assessment. DNA samples from all patients were analysed for mutations in COH1 by direct sequencing. Splice site mutations were characterised using reverse transcriptase PCR analysis from total RNA samples. In this series, we detected 25 different COH1 mutations; 19 of these were novel, including 9 nonsense mutations, 8 frameshift mutations, 4 verified splice site mutations, 3 larger in frame deletions, and 1 missense mutation. We observed marked variability of developmental and growth parameters. The typical facial gestalt was seen in 23/24 patients. Early onset progressive myopia was present in all the patients older than 5 years. Widespread pigmentary retinopathy was found in 12/14 patients assessed over 5 years of age. We present evidence for extended allelic heterogeneity of CS, with the vast majority of mutations leading to premature termination codons in COH1. Our data confirm the broad clinical spectrum of CS with some patients lacking even the characteristic facial gestalt and pigmentary retinopathy at school age.

[22q11.2 microdeletion syndrome: Analysis of the care pathway before the genetic diagnosis]. / Syndrome de microdélétion 22q11.2 : analyse du parcours patient avant le diagnostic génétique.

BACKGROUND: 22q11.2 deletion syndrome (22q11.2DS) is a very broad phenotypic spectrum disorder. It can affect many organs or systems. 22q11.2DS is the most common microdeletion syndrome in humans, with a prevalence ranging from one in every 2000 to one in 4000 newborns. It seems to be more prevalent than reported and under-recognized or undiagnosed because of its inherent clinical variability and heterogeneity. In France, 15,000 patients may be affected by this disease, more than half without knowing it. The aim of this study was to analyze the care pathway before the genetic diagnosis of 22q11.2DS. METHODS: We conducted a single-center, retrospective analysis of postnatally diagnosed patients recruited by the cytogenetic laboratory of Nancy (France) from January 2000 to December 2015. Clinical data were first collected by consulting the medical files of patients and then by calling them directly. Written informed consent was obtained and the study was approved by local research ethics boards. Data concerned only clinical features before the diagnosis. RESULTS: The cohort consisted of 32 individuals with 22q11.2DS. The average age at diagnosis was 9 years and 2 months and the median age was 2 years and 11 months. Fetal echography was abnormal in 15 pregnancies. During the neonatal period, the most important features were eating difficulties and congenital malformations (n=20), with a majority of complex heart diseases (n=16), dominated by conotruncal malformations (n=6). In case of malformation, the average age at diagnosis decreased to 2 years and 6 months. A congenital heart disease brought the average age of diagnosis down to 2 years and 6 months. Hypocalcemia and dysmorphism were also classical features (n=14). Before the age of 3 years, speech delay occurred in nine patients. After 3 years of age, rhinolalia was predominant (n=11). Academic disabilities were present in all subjects. At least 14 patients had a de novo deletion. Five patients were diagnosed within genetic counseling, with the deletion was inherited from the mother in three out of four cases. One was the monozygotic twin of a patient. Seven patients were diagnosed as adults. Four of them were diagnosed only because of the clinical presentation of their children or fetuses. Retrospectively, all adult patients had clinical signs suggesting the 22q11.2DS diagnosis. Relational disorders affected eight patients. None of them had been referred to the geneticist for this reason. In most cases, the pediatric cardiologist referred patients to the geneticist (n=9). Physiotherapists (n=15) and speech-language pathologists (n=12) were frequently requested but did not participate in the diagnosis. CONCLUSION: The present study highlights the difficulty of establishing the diagnosis when the major features of the 22q11.2DS are absent during the 1st months of life. This is particularly true when there is no congenital defect. Special attention must be given to speech disorders in childhood and neuropsychological disorders later in life. The association between 22q11.2DS and early-onset parkinson disease implies that adult neurologists should be aware of this diagnosis. For adult patients, familial occurrence is the most frequent cause of diagnosis in spite of clinical signs suggestive of 22q11.2DS. The management of these patients involves better information of medical and paramedical staff in order to refer them to the geneticist earlier in life.

[Sandifer's syndrome in a 5-month-old child with suspicion of infantile spasms]. / Syndrome de Sandifer chez une enfant de 5 mois admise pour des spasmes épileptiques.

Sandifer's syndrome is a dystonic movement disorder in infants with gastroesophageal reflux (GER). It is probably misdiagnosed as epileptic seizures. We report the case of a 5-month-old infant with no past medical history admitted to a pediatric unit for suspicion of infantile spasms. She presented with dystonic movements of the upper left limb with left blepharospasm and an occasional dystonic head posture. Physical examination, EEG, brain MRI, and blood analysis were normal. Since the baby experienced regurgitations, Sandifer's syndrome was suspected and confirmed by 24-h esophageal pH monitoring that documented pathological GER. The dystonic symptoms quickly disappeared under treatment with thickened infant formula and sodium alginate. Infantile spasms remain the first diagnosis to explore with axial or para-axial dystonic postural events. Sandifer's syndrome should be retained when neurological investigations are normal and abnormal movements disappear under treatment of proven GER. Prognosis is excellent.

30 months follow-up of an early enzyme replacement therapy in a severe Morquio A patient: About one case.

Patients under 5 years were not evaluated in the phase-3 study for enzyme replacement therapy (ERT) in MPS IV A. Here we describe the evolution of a severe Morquio A pediatric patient who was diagnosed at 19 months old and treated by ERT at 21 months old for the next 30 months. Applying the standard ERT protocol on this very young patient appeared to reduce his urinary excretion of glycosaminoglycans (GAGs); the improvements in both the 6 minute-walk test (6MWT) and the stair climb test, however, were no different than those reported in the nature history study. Additionally, this young patient experienced many ERT-associated side effects, and as a result a specific corticosteroid protocol (1 mg/kg of betamethasone the day before and 1 h before the ERT infusion) was given to avoid adverse events. Under these treatments, the height of this patient increased during the first year of the ERT although no more height gain was observed thereafter for 18 months. However, despite of ERT, his bone deformities (including severe pectus carinatum) actually worsened and his medullar cervical spine compression showed no improvement (thus needed decompression surgery). CONCLUSION: early ERT treatment did not improve the bone outcome in this severe MPS IV A patient after the 30 months-long treatment. A longer term follow up is required to further assess the efficacy of ERT on both the motor and the respiratory function of the patient.