Complex mode of inheritance in holoprosencephaly revealed by whole exome sequencing.

Holoprosencephaly (HPE) is the most common congenital cerebral malformation, characterized by impaired forebrain cleavage and midline facial anomalies. Heterozygous mutations in 14 genes have been associated with HPE and are often inherited from an unaffected parent, underlying complex genetic bases. It is now emerging that HPE may result from a combination of multiple genetic events, rather than from a single heterozygous mutation. To explore this hypothesis, we undertook whole exome sequencing and targeted high-throughput sequencing approaches to identify mutations in HPE subjects. Here, we report two HPE families in which two mutations are implicated in the disease. In the first family presenting two foetuses with alobar and semi-lobar HPE, we found mutations in two genes involved in HPE, SHH and DISP1, inherited respectively from the father and the mother. The second reported case is a family with a 9-year-old girl presenting lobar HPE, harbouring two compound heterozygous mutations in DISP1. Together, these cases of digenic inheritance and autosomal recessive HPE suggest that in some families, several genetic events are necessary to cause HPE. This study highlights the complexity of HPE inheritance and has to be taken into account by clinicians to improve HPE genetic counselling.

Fetal phenotypes in otopalatodigital spectrum disorders.

Otopalatodigital spectrum disorders (OPDSD) include OPD syndromes types 1 and type 2 (OPD1, OPD2), Melnick-Needles syndrome (MNS), and frontometaphyseal dysplasia (FMD). These conditions are clinically characterized by variable skeletal dysplasia associated in males, with extra-skeletal features including brain malformations, cleft palate, cardiac anomalies, omphalocele and obstructive uropathy. Mutations in the FLNA gene have been reported in most FMD and OPD2 cases and in all instances of typical OPD1 and MNS. Here, we report a series of 10 fetuses and a neonatally deceased newborn displaying a multiple congenital anomalies syndrome suggestive of OPDSD and in whom we performed FLNA analysis. We found a global mutation rate of 44%. This series allows expanding the clinical and FLNA mutational spectrum in OPDSD. However, we emphasize difficulties to correctly discriminate OPDSD based on clinical criteria in fetuses due to the major overlap between these conditions. Molecular analyses may help pathologists to refine clinical diagnosis according to the type and the location of FLNA mutations. Discriminating the type of OPDSD is of importance in order to improve the genetic counseling to provide to families.

Inverted duplication with deletion: first interstitial case suggesting a novel undescribed mechanism of formation.

Inverted duplications with terminal deletions are a well-defined family of complex rearrangements already observed for most of chromosome extremities. Several mechanisms have been suggested which could lead to their occurrence, either through non-homologous end joining, non-allelic homologous recombination, or more recently through an intrastrand fold-back mechanism. We describe here a patient with intellectual disability and pharmacoresistant epilepsy, for which array CGH analysis showed the first interstitial case of inverted duplication with deletion on chromosome 1p. Furthermore, SNP array analysis revealed an associated segmental isodisomy for the distal part of 1p, which led us to consider a replicative mechanism to explain this abnormality. This observation extends the range of this once telomeric rearrangement.

SHOX mutations in dyschondrosteosis (Leri-Weill syndrome).

Dyschondrosteosis (DCS) is an autosomal dominant form of mesomelic dysplasia with deformity of the forearm (Madelung deformity; ref. 3). Based on the observation of XY translocations (p22,q12; refs 4-6) in DCS patients, we tested the pseudoautosomal region in eight families with DCS and showed linkage of the DCS gene to a microsatellite DNA marker at the DXYS233 locus (Zmax=6.26 at theta=0). The short stature homeobox-containing gene (SHOX), involved in idiopathic growth retardation and possibly Turner short stature, maps to this region and was therefore regarded as a strong candidate gene in DCS. Here, we report large-scale deletions (in seven families) and a nonsense mutation (in one family) of SHOX in patients with DCS and show that Langer mesomelic dwarfism results from homozygous mutations at the DCS locus.

Mutations in EDARADD account for a small proportion of hypohidrotic ectodermal dysplasia cases.

BACKGROUND: Hypohidrotic ectodermal dysplasia (HED) is characterized by abnormal development of the eccrine sweat glands, hair and teeth. The X-linked form of the disease, caused by mutations in the EDA gene, represents the majority of HED cases. Autosomal dominant and recessive forms occasionally occur and result from mutations in at least two other genes: EDAR and EDARADD. EDARADD interacts with the TAB2/TRAF6/TAK1 complex, which is necessary for NF-kappaB activation by EDAR. OBJECTIVES: To determine frequency of EDARADD, TRAF6, TAB2 and TAK1 mutations in HED. MATERIALS AND METHODS: We have screened 28 familial or sporadic HED cases with no mutations in the EDA and EDAR genes for EDARADD, TRAF6, TAB2 and TAK1 mutations. RESULTS: We identified one EDARADD 6-bp homozygous in-frame deletion (c.402-407del, p.Thr135-Val136del) in a patient born to consanguineous parents. Functional studies showed that the p.Thr135-Val136del impaired the EDAR-EDARADD interaction and then severely inhibited NF-kappaB activity. In the remaining 27 patients, we failed to find causative mutations in EDARADD, or in TRAF6, TAB2 or TAK1. CONCLUSIONS: Our study demonstrates that EDARADD mutations are not a frequent cause of HED, while mutations in TRAF6, TAB2 and TAK1 may not be implicated in this disease.

[Adverse obstetric and perinatal outcome with in vitro fertilization technology: A French nationwide population-based study]. / Risques de morbidité maternelle et périnatale en fécondation in vitro : une étude nationale de cohorte française.

OBJECTIVES: The objective of this study was to quantify the risk of maternal and perinatal morbidity with in vitro fertilization (IVF) technology compared to non-IVF pregnancies in a recent French national cohort. METHOD: The data was extracted from the hospital information data system, including all pregnancies with a delivery from 2013 to 2016. The risks of preterm birth, maternal morbidity (venous and arterial thrombosis, gestational diabetes, vascular disorders, placenta previa, placenta abruption), hypotrophy and congenital malformation were compared in both groups in univariate and multivariate analysis after adjustment on the characteristics of women (age, parity, obesity, tobacco dependence, history of diabetes or high blood pressure), multiple deliveries and sex of children. RESULTS: In all, 2,875,662 pregnancies and 2,922,712 births were analyzed, of which 49,224 were derived from IVF (1.7%). In multivariate analysis, all risks were significantly higher in IVF: premature deliveries (ORajusted=1.28; CI95%=1.24-1.32), maternal morbidity (ORajusted=1.24; CI95%=1.21-2.28), (mainly for thrombosis venous, placenta previa and placenta abruption). The risks of hypotrophy (ORajusted=1.13; CI95%=1.10-1.16) and congenital malformations (ORajusted=1.11; CI95%=1.05-1.17) were slightly increased. CONCLUSION: The results of this study on a large cohort of recent births in France confirm that there was an increased risk of maternal and perinatal morbidities in IVF. These risks were similar to those published in the international literature. This study is the starting point for a forthcoming surveillance.

[Autopsy findings related to Down's syndrome: 101 cases]. / Fréquence des malformations associées à la trisomie 21: à propos de 101 cas foetopathologiques.

OBJECTIVES: To analyze the spectrum of congenital malformations among fetuses with Down's syndrome sent for necropsy. Materials and methods. Necropsies following medical termination of pregnancy during the second and third trimester were performed during a 4 year period. RESULTS: The incidence of each malformation was determined. Talipes equinovarus and aberrant lobation of the lung were present in 6% of cases. We are able to state precisely the incidence of 11 pairs of ribs: 11%. CONCLUSION: A precise knowledge about Down's syndrome associated malformations is essential for genetic counselling. The exact incidence of each sign is important to lead ultrasound examination when this syndrome is revealed.

[The noninvasive prenatal testing for Down's Syndrome. Retrospective study of 8821 patients]. / Le dépistage prénatal non invasif de la trisomie 21. Étude rétrospective à propos de 8821 patientes.

OBJECTIVE: To demonstrate the decrease in intrauterine invasive procedures through analysis of DNA fetoplacental free circulating in maternal blood: Non Invasive Prenatal Test (NIPT), in Prenatal Diagnosis Center of American Hospital of Paris (AHP). MATERIALS AND METHODS: Retrospective descriptive study of 8821 patients in Prenatal Diagnosis Center at the AHP between 01/01/2012 and 09/25/2014. The NIPT is available to patients since 1st January 2013. RESULTS: The number of invasive procedures decreased significantly (P<0.0001) between 2012 (n=1177, i.e. 42 % of the global activity of the Prenatal Diagnosis Center at the AHP in 2012) and 2013 (n=987 or 28.5 %) and between 2013 and 2014 (n=599 or 23.4 %). The NIPT calculated performance statistics are: sensitivity≥99.9 %; specificity=99.8 %; Positive Predictive Value=90.4 %; Negative Predictive Value≥99.9 %; False Positives=3. While the actual screening statistic values are: sensitivity≥95.4 %; specificity=82.5 %; Positive Predictive Value=6.5 %; Negative Predictive Value=99.9 %; False Positives=1197. The NIPT has reduced the number of invasive procedures at the Prenatal Diagnosis Center at the AHP. The NIPT performances are superior to those of the actual screening.

Homozygosity mapping of a Dyggve-Melchior-Clausen syndrome gene to chromosome 18q21.1.

Dyggve-Melchior-Clausen syndrome (DMC) is an autosomal recessive condition characterised by short trunk dwarfism, scoliosis, microcephaly, coarse facies, mental retardation, and characteristic radiological features. X rays show platyspondyly with double vertebral hump, epiphyseal dysplasia, irregular metaphyses, and a characteristic lacy appearance of the iliac crests. Electron microscopy of chondrocytes have shown widened cisternae of rough endoplasmic reticulum and biochemical analyses have shown accumulation of glucosaminoglycan in cartilage, but the pathogenesis of DMC remains unexplained. Here, we report on the homozygosity mapping of a DMC gene to chromosome 18q21.1 in seven inbred families (Zmax=9.65 at theta=0 at locus D18S1126) in the genetic interval (1.8 cM) defined by loci D18S455 and D18S363. Despite the various geographical origins of the families reported here (Morocco, Tunisia, Portugal, and Lebanon), this condition was genetically homogeneous in our series. Continuing studies will hopefully lead to the identification of the disease causing gene.

Twelve novel mutations in the tissue-nonspecific alkaline phosphatase gene (ALPL) in patients with various forms of hypophosphatasia.

Hypophosphatasia is a rare inherited disorder characterized by defective bone mineralization and deficiency of serum and tissue liver/bone/kidney tissue alkaline phosphatase (L/B/K ALP) activity. We report here the characterization of tissue-nonspecific alkaline phosphatase (TNSALP) gene mutations in a series of 11 families affected by various forms of hypophosphatasia. Nineteen distinct mutations were found, 7 of which were previously reported. Eleven of the 12 new mutations were missense mutations (Y11C, A34V, R54H, R135H, N194D, G203V, E218G, D277Y, F310G, A382S, V406A), the last one (998-1G>T) was a mutation affecting acceptor splice site.

Chediak-Higashi syndrome associated with maternal uniparental isodisomy of chromosome 1.

Chediak-Higashi syndrome (CHS) is a rare autosomal recessive disorder (incidence around 1 in 106 births), characterised by a complex immunologic defects, reduced pigmentation, and presence of giant granules in many different cell types. It most likely results from defective organellar trafficking or protein sorting. The causative gene (LYST) has recently been identified and shown to be homologous to the beige locus in the mouse. CHS has always been reported associated with premature-termination-codon mutations in both alleles of LYST. We report a unique patient with CHS, who was homozygous for a stop codon in the LYST gene on chromosome 1 and who had a normal 46,XY karyotype. The mother was found to be a carrier of the mutation, whereas the father had two normal LYST alleles. Non-paternity was excluded by the analysis of microsatellite markers from different chromosomes. The results of 13 informative microsatellite markers spanning the entire chromosome 1 revealed that the proband had a maternal isodisomy of chromosome 1 encompassing the LYST mutation. The proband's clinical presentation also confirms the absence of imprinted genes on chromosome 1.

A sandwich method of enzyme immunoassay. III. Assay for human beta-2 microglobulin compared with radioimmunoassay.

A sandwich enzyme immunoassay has been developed to measure human beta-2 microglobulin (beta 2m) in bilogical fluids. beta 2m is first bound by specific antibody covalently coupled to microcrystalline cellulose. The solid phase is washed and reincubated with glucose oxidase-labeled anti-beta 2m antibody. After washing, the enzymic activity of the solid phase is measured by incubation with the appropriate chromogenic substrate. The OD is directly related to the quantity of beta 2m to be measured. A second sandwich assay has also been developed which uses plastic microplates coated with the IgG fraction of rabbit anti-beta 2m serum. Reproducible results are obtained in the range 2-150 and 0.75-48 microgram/l respectively. These tests detect 17 fmoles of beta 2m. Assays of 27 sera showed good agreement between these two enzyme immunoassay methods and two radioimmunoassays.

Apparent Sotos syndrome (cerebral gigantism) in a child with trisomy 20p11.2-p12.1 mosaicism.

We report on a child with apparent Sotos syndrome (cerebral gigantism) and partial duplication of the short arm of chromosome 20 mosaicism. Trisomy 20p11.2-p12.1 was diagnosed using cytogenetic and FISH studies. The somatostatin receptor 4 (SSTR4) gene is included in the duplicated segment. This suggests that a dosage effect of this gene might be related to some of the clinical findings observed in our patient. The present observation emphasizes the importance of chromosome analysis in patients with well-delineated but sporadic conditions.

Comparative study of gamma glutamyl transferase, alkaline phosphatase and its alpha 1 isoenzyme as biological indicators of liver metastases.

Biological detection of liver metastases represents an important factor in the surveillance of the course of cancerous affections. The authors present a report on a potential new indicator, the isoenzyme of alkaline phosphatase migrating to the alpha 1 region (alpha 1 ALP). In comparison to those tests considered the most sensitive at present-gamma glutamyl transferase and total alkaline phosphatase-this alpha 1 isoenzyme appears more sensitive and more specific, capable of detecting 97% of liver metastases with a specificity of 90%.

[Metabolic and genetic investigations in childhood cardiomyopathies]. / Explorations métaboliques et génétiques des cardiomyopathies de l'enfant.

Metabolic cardiomyopathy of babies and children accounts for approximately 15% of all cardiomyopathies presenting at these ages. The confirmation of the aetiology is essential for treatment, which is rarely curative. For establishing a prognosis which is often poor, and, above all, for family counselling in cases of mendelian transmission or mitochondrial disease. Cardiomyopathy due to glycogen (Pompe's disease) or mucopolysaccharide (Hurler's disease) disorders are easy to diagnose because of obvious extracardiac manifestations. The diagnosis of the enzyme deficiency only requires a blood and/or urine test. Cardiomyopathies due to a deficit of oxidative metabolism are usually associated with multi-system abnormalities but may be isolated or the presenting sign of the deficit. The diagnosis should be suspected in cases of a positive family history of cardiomyopathy or sudden death, of co-sanguinity, of unusual or unexplained extracardiac disease, of atypical ECG changes or of hypoglycaemia. Chromatography of organic acids, analysis of acylcarnitines and -oxidation of the fatty acid oxidation. Of these conditions, only primary carnitine deficits are curable. The diagnosis of mitochondrial cardiomyopathy is based on the ratios of oxidoreduction and, above all, on spectrophotometric analysis of the respiratory chain complexes in skeletal or cardiac muscle (when the heart is the only organ involved). Genetic counselling is difficult and punctual mutations or deletions of mitochondrial DNA are rarely observed, and also few nuclear genes coding for the proteins of the respiratory chain have been identified to this day.

SHOX gene mutations and deletions in dyschondrosteosis or Leri-Weill syndrome.

Dyschondrosteosis is an autosomal dominant form of mesomelic dysplasia that is often combined with a deformity of the forearms called Madelung deformity. Based on the observation of X-Y translocations (p22,q12) in patients with dyschondrosteosis, the authors tested the pseudoautosomal region in eight affected families and showed linkage of the dyschondrosteosis gene to a microsatellite DNA marker at the DXYS233 locus (Zmax = 6.26 at theta = 0). Since the short stature homeobox-containing gene (SHOX) involved in idiopathic growth retardation and possibly Turner syndrome maps to this region, SHOX was regarded as a strong candidate gene for dyschondrosteosis. This article reports the detection of large-scale SHOX deletions in seven of the eight families and a nonsense mutation of SHOX in the remaining family affected with dyschondrosteosis. Additional evidence suggests that Langer mesomelic dwarfism results from homozygous mutations at the genetic locus responsible for dyschondrosteosis.

[French validation of a Minor Morphologic Anomalies Scale in schizophrenic patients and their parents]. / Validation française d'une échelle d'Anomalies Morphologiques Mineures appliquée à des patients schizophrènes et à leurs parents.

UNLABELLED: Minor Physical Anomalies represent valuable indices of disturbance in early neurodevelopment. They are frequently observed in individuals with various brain disorders, including mental retardation, autism, epilepsy, hyperactivity, foetal alcohol syndrome and schizophrenia. The high prevalence of Minor Physical Anomalies in schizophrenia provides considerable support for a neurodevelopmental model in this disorder. However, studies in large sample using standardised scale are lacking. Such studies are needed in order to confirm their actual frequency and study the clinical correlates or morphological anomalies. OBJECTIVE: The aim of this study was to revise and validate a French version of a scale designed for the evaluation of Minor Physical Anomalies in adult psychiatric patients and notably in patients with schizophrenia. METHODOLOGY: The scale was revised from the Waldrop scale. The choice of items was done on the basis of frequency, reliability in the adult, reliability of rating. Some new items, related to know syndroms with comportmental symptoms were added. Both raters had previously had a short initiation to the rating of the scale. Interrater reliability between two examiners, blind with regards to the diagnosis was evaluated. RESULTS: The interrater reliability was good, with an intraclass correlation coefficient at 0.97. Patients had significantly more minor physical anomalies than comparison subjects, and also more Minor Physical Anomalies than their parents. Fathers and mothers of these schizophrenic patients had significantly more Minor Physical Anomalies than normal comparison subjects. CONCLUSION: Although the evaluation of physical anomalies relies on subjective appreciation of normal vs abnormal, the revised version of minor physical anomalies scale (French version) was found to be a reliable tool, provided that a short initiation to the rating is performed. The scale differentiated schizophrenic patients from their parents, and the latter from the normal controls. A lot of questions remains unanswered concerning the neurodevelopmental hypothesis of schizophrenia. This scale appeared as a useful complementary tool to help in the determination of the developmental phenotypic status of the patients enrolled in pathophysiological studies aiming the identification of developmental factors in schizophrenia.

[Rectal self-mutilation, rectal bleeding and Prader-Willi syndrome]. / Automutilation rectale, rectorragies et syndrome de Prader-Willi.

UNLABELLED: Prader-Willi syndrome is a genetic disorder characterized by infantile hypotonia, obesity, hypogonadism and mental retardation. Individuals with Prader-Willi syndrome manifest a severe skin picking behavior, including rectal picking. CASE REPORT: We report the case of a girl (12 years old) with this syndrome in whom rectal picking resulted in rectal bleeding and solitary rectal ulcer. CONCLUSION: Caregivers of children with Prader-Willi syndrome should be aware of a potential rectal picking behavior, which results in significant bleeding. Early recognition of such a behavior helps to avoid misdiagnosis.

[Confined placental mosaicism: definition, consequences and outcome]. / Mosaïques confinées au placenta: définition, conséquences et conduite à tenir.

Confined placental mosaicism (CPM) occurs in approximately 2 per cent of viable pregnancies studies by chorionic villus sampling. The great majority of pregnancies with confined placental mosaicism proceed uneventfully, resulting in normal liveborn infants. However, a few specific chromosomal abnormalities have been associated with fetal growth retardation. Fetal karyotype should be checked by amniocentesis and such pregnancies should have careful ultrasound follow-up.