Role of chromosomal imbalances in the pathogenesis of DSD: A retrospective analysis of 115 prenatal samples.

Differences of sex development (DSDs) are a group of congenital conditions characterized by a discrepancy between chromosomal, gonadal, and genital sex development of an individual, with significant impact on medical, psychological and reproductive life. The genetic heterogeneity of DSDs complicates the diagnosis and almost half of the patients remains undiagnosed. In this context, chromosomal imbalances in syndromic DSD patients may help to identify new genes implicated in DSDs. In this study, we aimed at describing the burden of chromosomal imbalances including submicroscopic ones (copy number variants or CNVs) in a cohort of prenatal syndromic DSD patients, and review their role in DSDs. Our patients carried at least one pathogenic or likely pathogenic chromosomal imbalance/CNV or low-level mosaicism for aneuploidy. Almost half of the cases resulted from an unbalanced chromosomal rearrangement. Chromosome 9p/q, 4p/q, 3q and 11q anomalies were more frequently observed. Review of the literature confirmed the causative role of CNVs in DSDs, either in disruption of known DSD-causing genes (SOX9, NR0B1, NR5A1, AR, ATRX, …) or as a tool to suspect new genes in DSDs (HOXD cluster, ADCY2, EMX2, CAMK1D, …). Recurrent CNVs of regulatory elements without coding sequence content (i.e. duplications/deletions upstream of SOX3 or SOX9) confirm detection of CNVs as a mean to explore our non-coding genome. Thus, CNV detection remains a powerful tool to explore undiagnosed DSDs, either through routine techniques or through emerging technologies such as long-read whole genome sequencing or optical genome mapping.

A series of 38 novel germline and somatic mutations of NIPBL in Cornelia de Lange syndrome.

Cornelia de Lange syndrome is a multisystemic developmental disorder mainly related to de novo heterozygous NIPBL mutation. Recently, NIPBL somatic mosaicism has been highlighted through buccal cell DNA study in some patients with a negative molecular analysis on leukocyte DNA. Here, we present a series of 38 patients with a Cornelia de Lange syndrome related to a heterozygous NIPBL mutation identified by Sanger sequencing. The diagnosis was based on the following criteria: (i) intrauterine growth retardation and postnatal short stature, (ii) feeding difficulties and/or gastro-oesophageal reflux, (iii) microcephaly, (iv) intellectual disability, and (v) characteristic facial features. We identified 37 novel NIPBL mutations including 34 in leukocytes and 3 in buccal cells only. All mutations shown to have arisen de novo when parent blood samples were available. The present series confirms the difficulty in predicting the phenotype according to the NIPBL mutation. Until now, somatic mosaicism has been observed for 20 cases which do not seem to be consistently associated with a milder phenotype. Besides, several reports support a postzygotic event for those cases. Considering these elements, we recommend a first-line buccal cell DNA analysis in order to improve gene testing sensitivity in Cornelia de Lange syndrome and 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.

Split hand/foot malformation with long-bone deficiency and BHLHA9 duplication: report of 13 new families.

Split hand/foot malformation (SHFM) with long-bone deficiency (SHFLD, MIM#119100) is a rare condition characterized by SHFM associated with long-bone malformation usually involving the tibia. Previous published data reported several unrelated patients with 17p13.3 duplication and SHFLD. Recently, the minimal critical region had been reduced, suggesting that BHLHA9 copy number gains are associated with this limb defect. Here, we report on 13 new families presenting with ectrodactyly and harboring a BHLHA9 duplication.

Array-CGH Analysis Suggests Genetic Heterogeneity in Rhombencephalosynapsis.

Rhombencephalosynapsis is an uncommon, but increasingly recognized, cerebellar malformation defined as vermian agenesis with fusion of the hemispheres. The embryologic and genetic mechanisms involved are still unknown, and to date, no animal models are available. In the present study, we used Agilent oligonucleotide arrays in a large series of 57 affected patients to detect candidate genes. Four different unbalanced rearrangements were detected: a 16p11.2 deletion, a 14q12q21.2 deletion, an unbalanced translocation t(2p;10q), and a 16p13.11 microdeletion containing 2 candidate genes. These genes were further investigated by sequencing and in situ hybridization. This first microarray screening of a rhombencephalosynapsis series suggests that there may be heterogeneous genetic causes.

Intragenic rearrangements in LARGE and POMGNT1 genes in severe dystroglycanopathies.

Dystroglycanopathies are a heterogeneous group of muscular dystrophies with autosomal recessive inheritance characterized by abnormal glycosylation of alpha-dystroglycan. The most severe phenotypes are Walker-Warburg Syndrome (WWS) and muscle-eye-brain disease (MEB) presenting with lissencephaly type II (LIS II) and in which muscular dystrophy is associated with mental retardation and eye abnormalities. To date, six distinct genes, POMT1, POMT2, POMGNT1, FKTN, FKRP, LARGE and recently in one case DPM3, have been shown to be involved in dystroglycanopathies. Genomic sequencing alone is still frequently used for diagnosis purpose, not allowing detection of intragenic rearrangements at the heterozygous state contrarily to RNA analysis, quantitative PCR and CGH array analysis. These latter methods enabled us to identify four new intragenic rearrangements in the LARGE gene in three fetuses with WWS, born to two unrelated families: deletion of exons 9-10 and duplication of introns 1-4 for the first family and deletion of exons 4 and 7 for the second one; and a deletion of the last six exons of the POMGNT1 gene in two unrelated MEB patients. Genomic dosage studies using emerging tools such as CGH array should be included in routine molecular analysis of dystroglycanopathies, not only for the screening of the LARGE gene in which this kind of mutation seems to be more frequent than point mutations, but also for the other involved genes, especially in severe clinical cases.

Diagnosis of fetal urinary tract malformations: prenatal management and postnatal outcome.

OBJECTIVE: To evaluate prenatal management and to define the criteria of gravity for accurate assessment of the renal and overall prognosis of fetuses presenting malformations of the urinary tract. METHODS: We carried out a retrospective study of 127 cases of urinary tract malformation. We carried out descriptive statistical and univariate analyses as a function of severity criteria and the outcome of pregnancy. RESULTS: One-third of fetuses presented associated extrarenal malformations and 10% of the karyotypes were abnormal. There were more abortions in case of decrease in amniotic fluid volume (p < 0.001), extent of renal damage (p < 0.05), presence of associated extrarenal malformations (p < 0.05), early diagnosis of the malformation (p < 0.001) and presence of chromosomal syndrome (p = 0.01). In our study, there was an excellent correlation between prenatal data and pathological findings for the fetus following abortions for medical reasons or obtained during the surveillance of live-born children. Fetal biochemistry made very little contribution. CONCLUSION: In cases of urinary tract malformation, this work confirms the need for regular and frequent ultrasound scans, checking for the echographic factors indicative of gravity and for adapted karyotyping. It also demonstrates that pluridisciplinary management is necessary for the prenatal evaluation of renal and overall fetal prognosis.

[Can we explain the sudden infant death syndrome? About a series of 80 cases with an autopsy in Rennes University Hospital, France in the period 1994-2007]. / Peut-on expliquer la mort inattendue du nourrisson? Réflexions à partir d'une série de 80 cas autopsiés au CHU de Rennes entre 1994 et 2007.

Sudden infant death syndrome (SIDS) is a huge hardship for parents, but also for health professionals. In 2007, 210 cases occurred in France, corresponding to a crude rate of 31.8 for 100,000 births. Between 1994 and 2007, 140 children of less than 2 years old were examined in the reference centre for SIDS in Rennes, France. We included in our study the children who were aged more than 28 days at death date, did not have a known lethal disease and were autopsied. A total of 80 children fulfilled those criteria. Post-mortem investigation included an autopsy, clinical and paraclinical exams (blood test, radiography, CT-scan...), and investigation of the circumstances of the death. Most of the cases were boys and were 2- to 5-month old. Ventral decubitus and gastrointestinal symptoms were often present. Autopsy gave elements about the causes of death in 23 cases and the other exams performed frequently showed an infectious viral context. Thanks to prevention and information campaigns about childcare done in the 1990s, SIDS incidence has largely decreased in France, but it is still too frequent. In our opinion, advice needs to be given again and again, especially concerning safe sleep practices, in order to increase adherence to these recommendations. Moreover, research should be continued to better understand this unexplained syndrome.

Genotype-phenotype correlations in fetuses and neonates with autosomal recessive polycystic kidney disease.

The prognosis of autosomal recessive polycystic kidney disease is known to correlate with genotype. The presence of two truncating mutations in the PKHD1 gene encoding the fibrocystin protein is associated with neonatal death while patients who survive have at least one missense mutation. To determine relationships between genotype and renal and hepatic abnormalities we correlated the severity of renal and hepatic histological lesions to the type of PKHD1 mutations in 54 fetuses (medical pregnancy termination) and 20 neonates who died shortly after birth. Within this cohort, 55.5% of the mutations truncated fibrocystin. The severity of cortical collecting duct dilatations, cortical tubule and glomerular lesions, and renal cortical and hepatic portal fibrosis increased with gestational age. Severe genotypes, defined by two truncating mutations, were more frequent in patients of less than 30 weeks gestation compared to older fetuses and neonates. When adjusted to gestational age, the extension of collecting duct dilatation into the cortex and cortical tubule lesions, but not portal fibrosis, was more prevalent in patients with severe than in those with a non-severe genotype. Our results show the presence of two truncating mutations of the PKHD1 gene is associated with the most severe renal forms of prenatally detected autosomal recessive polycystic kidney disease. Their absence, however, does not guarantee survival to the neonatal period.

Embryology of neural tube defects: information provided by associated malformations.

OBJECTIVES: To get information about embryologic mechanisms of neural tube defects (NTD), by studying the associated malformations. METHODS: Eighty three cases of NTD, seen at the prenatal diagnosis unit of Rennes University Hospital (France) between May 1999 and December 2002, were retrospectively studied. Cases with chromosomal anomalies (5/83), cases without available karyotype or pathologic examination were excluded. 24 spina bifida, and 27 cephalic forms (anencephalies, exencephalies, and encephaloceles) were thus analyzed. RESULTS: Only 22/51 cases (43%) were strictly isolated NTD. Anomalies of tissues arising from neural crests were noted in 8/51 fetuses (16%), midline or lateralization anomalies in 12/51 (24%), and anomalies of mesoblastic tissues in 17/51 (33%). An already known syndrome was found in 4/51 cases (8%). CONCLUSION: NDT are more extensive congenital damages that would suggest the restrictive terminology. That prompts to assess cautiously prenatal diagnosis of NTD, and to get detailed pathological examination after termination of pregnancy.

Molecular heterogeneity in fetal forms of type II lissencephaly.

Type II lissencephaly (type II LIS) is a group of autosomal recessive congenital muscular dystrophies (CMD) associated with defects in alpha-DG O-glycosylation, which comprises Walker-Warburg syndrome, Fukuyama cerebral and muscular dystrophy, or muscle-eye-brain disease. The most severe forms of these diseases often have a fetal presentation and lead to a pregnancy termination. We report here the first molecular study on fetal type II LIS in a series of 47 fetuses from 41 unrelated families. Sequencing of the different genes known to be involved in alpha-DG O-glycosylation allowed the molecular diagnosis in 22 families: involvement of POMT1 was demonstrated in 32% of cases, whereas POMGNT1 and POMT2 were incriminated in 15% and in 7% of cases, respectively. We found 30 different mutations in these three genes, 25 were described herein for the first time, 15 in POMT1, and five in POMT2 and POMGNT1. Despite sequencing of FKRP, FCMD, and LARGE, no definitive molecular diagnosis could be made for the other half of our cases. Preliminary results concerning genotype-phenotype correlations show that the choice of the first gene sequenced should depend on the clinical severity of the type II LIS; POMT1 and POMT2 for severest clinical picture and POMGNT1 for milder disease. The other genes, FKRP, FCMD, and LARGE, seem not to be implicated in the fetal form of CMD.

[Prenatal diagnosis of sirenomelia]. / Diagnostic anténatal d'une sirénomélie.

Sirenomelia sequence associates a fusion of inferior legs with renal anomalies until bilateral agenesis. It is a rare and lethal polymalformation. The purpose of the ultrasonographic study is to identify the sirenomelia as early as possible during pregnancy and to differentiate it from caudal regression syndrome. A case of sirenomelia diagnosed early is reported together with a review of the literature. The ultrasonographic diagnosis, associated defects, the interest of color Doppler study of abdominal vasculature are discussed. Antenatal ultrasonographic diagnosis should be obtained as early as possible, before 20th gestational week at the latest. Color Doppler is helpful to confirm the diagnosis in case of bilateral renal agenesis. The main differences between sirenomelia and caudal regression syndrome (which requires a very different genetic counselling) are summarized in a table.

Perinatal-lethal Gaucher disease.

Gaucher disease is a lysosomal storage disease caused by glucocerebrosidase deficiency. Although purely visceral in most cases, some Gaucher disease patients have neurological signs. Signs of Gaucher disease appear after a symptom-free period, except in rare cases with fetal onset. The description of such cases was based mainly on single reports and siblings. We report here a series of perinatal-lethal Gaucher disease cases highlighting the specificity of this phenotype. We retrospectively studied eight original cases of proven Gaucher disease with fetal onset. Non-immune hydrops fetalis was present in all cases but one, and associated with hepatosplenomegaly, ichthyosis, arthrogryposis, and facial dysmorphy. The similarities between our cases and 33 previously described cases allow us to better delineate the perinatal-lethal Gaucher disease phenotype. Hydrops fetalis, in utero fetal death and neonatal distress are prominent features. When hydrops is absent, neurological involvement begins in the first week and leads to death within three months. Hepatosplenomegaly is a major sign, and associated with ichthyosis, arthrogryposis, and facial dysmorphy in some 35-43% of cases. Perinatal-lethal Gaucher disease is a specific entity defined by its particular course and signs that are absent in classical type 2 Gaucher disease. Our study provides clues to the diagnosis of this likely underdiagnosed condition, which must be biochemically confirmed in order to propose appropriate genetic counselling.

Unusual fan shaped ossification in a female fetus with radiological features of boomerang dysplasia.

We report on a female fetus of 24 weeks whose clinical and radiological findings were compatible with boomerang dysplasia (BD). However, histopathology was unusual with a lateral fan shaped diaphyseal ossification. This has never been described either in typical atelosteogenesis I (AT-I) or in BD. The purpose of this report is to find out if this condition is a separate lethal bone dysplasia or another histological feature of the nosological group of AT-I and BD.

[Adenocarcinoma of Brunner's glands: an entity exceptionally described. Report of a case]. / Les adénocarcinomes brünnériens : une entité exceptionnellement décrite. A propos de deux cas.

The authors report two cases of adenocarcinoma arising from Brünner's glands. The diagnosis was made on histological, histochemical and lectin-histochemical grounds. Brünner's glands carcinoma cells were alike and located very close to normal Brünner's glands. Brünner's glands carcinoma cells contained neutral glycoproteins and were positive for Concanavalin A.

[Giant juvenile fibroadenoma in an adolescent. A case report]. / Le fibroadénome géant juvénile chez l'adolescente. A propos d'un cas.

Fibroadenomas occupy the first place, in terms of prevalence, among benign breast disorders in adolescent girls. Juvenile giant fibroadenoma is a special though rare form, which must be recognised in terms of differential diagnosis from virginal hyperplasia in its asymmetrical early form and phylloid tumours, the prognosis of which is different. The authors describe the clinical and pathological features necessary for diagnosis and report the results of breast reconstruction after excision via a lateral radial approach in a 14-year-old adolescent girl.

[Breast cancer associated with pregnancy. Nine case reports. Review of the literature and current update]. / Cancer du sein associé à la grossesse. A propos de 9 observations. Revue de la littérature et mise au point.

The authors report nine personal cases in a review of the literature concerning cancers of the breast associated with pregnancy and lactation (until a year post-partum). The diagnosis of the illness is reported to be difficult in pregnant women and it is necessary to use fully all the diagnostic procedures available and in particular cytology and histology. Surgery is urgent. It is classical practice to carry out a mastectomy with axillary clearance. Nevertheless more conservative treatments are now being suggested. The principal problem of therapy is linked to the effects of adjuvant therapy on the fetus be they radiotherapy or chemotherapy, particularly because it is very important that treatments should be thorough and start early in the pregnancy. The overall prognosis is bad because pregnancy seems above all to aggravate serious forms of the disease.

[Accelerated decalcification using microwaves]. / Décalcification accélérée par les micro-ondes.

The authors report a protocol for microwave-accelerated decalcification. In comparison to decalcification at ambient temperature, decalcification using the microwave oven is reduced by a factor of 9 for trephine biopsies and by a factor of 11 for bone samples.