PubMed Health⌕ Search

Biomedical subjects

J Amiel

Publications and source records attributed to J Amiel.

At least 19 recordsLinked to original sources
PubMed2006

Array-based comparative genomic hybridisation identifies high frequency of cryptic chromosomal rearrangements in patients with syndromic autism spectrum disorders.

BACKGROUND: Autism spectrum disorders (ASD) refer to a broader group of neurobiological conditions, pervasive developmental disorders. They are characterised by a symptomatic triad associated with qualitative changes in social interactions, defect in communication abilities, and repetitive and stereotyped interests and activities. ASD is prevalent in 1 to 3 per 1000 people. Despite several arguments for a strong genetic contribution, the molecular basis of a most cases remains unexplained. About 5% of patients with autism have a chromosome abnormality visible with cytogenetic methods. The most frequent are 15q11-q13 duplication, 2q37 and 22q13.3 deletions. Many other chromosomal imbalances have been described. However, most of them remain undetectable using routine karyotype analysis, thus impeding diagnosis and genetic counselling. METHODS AND RESULTS: 29 patients presenting with syndromic ASD were investigated using a DNA microarray constructed from large insert clones spaced at approximately 1 Mb intervals across the genome. Eight clinically relevant rearrangements were identified in 8 (27.5%) patients: six deletions and two duplications. Altered segments ranged in size from 1.4 to 16 Mb (2-19 clones). No recurrent abnormality was identified. CONCLUSION: These results clearly show that array comparative genomic hybridisation should be considered to be an essential aspect of the genetic analysis of patients with syndromic ASD. Moreover, besides their importance for diagnosis and genetic counselling, they may allow the delineation of new contiguous gene syndromes associated with ASD. Finally, the detailed molecular analysis of the rearranged regions may pave the way for the identification of new ASD genes.

Adolescent↗
PubMed2006

Mutations of the RET gene in isolated and syndromic Hirschsprung's disease in human disclose major and modifier alleles at a single locus.

BACKGROUND: In Hirschsprung's disease (HSCR), a hypomorphic allele of a major gene, RET, accounts for most isolated (non-syndromic) cases, along with other autosomal susceptibility loci under a multiplicative model. However, some syndromic forms of HSCR are monogenic entities, for which the disease causing gene is known. OBJECTIVE: To determine whether RET could be considered a modifier gene for the enteric phenotype on the background of a monogenic trait. METHODS: The syndromic HSCR entities studied were congenital central hypoventilation (CCHS) and Mowat-Wilson syndrome (MWS), caused by PHOX2B and ZFHX1B gene mutations, respectively. The RET locus was genotyped in 143 CCHS patients, among whom 44 had HSCR, and in 30 MWS patients, among whom 20 had HSCR. The distribution of alleles, genotypes, and haplotypes was compared within the different groups. To test the interaction in vivo, heterozygous mice were bred for a null allele of Phox2b and Ret genes. RESULTS: RET was shown to act as a modifier gene for the HSCR phenotype in patients with CCHS but not with MWS. The intestine of double heterozygote mice was indistinguishable from their littermates. A loss of over 50% of each gene function seemed necessary in the mouse model for an enteric phenotype to occur. CONCLUSIONS: In CCHS patients, the weak predisposing haplotype of the RET gene can be regarded as a quantitative trait, being a risk factor for the HSCR phenotype, while in MWS, for which the HSCR penetrance is high, the role of the RET predisposing haplotype is not significant. It seems likely that there are both RET dependent and RET independent HSCR cases.

Alleles↗
PubMed2005

Phenotypic spectrum of CHARGE syndrome in fetuses with CHD7 truncating mutations correlates with expression during human development.

BACKGROUND: The acronym CHARGE refers to a non-random cluster of malformations including coloboma, heart malformation, choanal atresia, retardation of growth and/or development, genital anomalies, and ear anomalies. This set of multiple congenital anomalies is frequent, despite rare patients with normal intelligence, and prognosis remains poor. Recently, CHD7 gene mutations have been identified in CHARGE patients; however, the function of CHD7 during development remains unknown. METHODS: We studied a series of 10 antenatal cases in whom the diagnosis of CHARGE syndrome was suspected, considering that a careful pathological description would shed light on the CHD7 function during development. CHD7 sequence analysis and in situ hybridisation were employed. RESULTS: The diagnosis of CHARGE syndrome was confirmed in all 10 fetuses by the identification of a CHD7 heterozygous truncating mutation. Interestingly, arhinencephaly and semi-circular canal agenesis were two constant features which are not included in formal diagnostic criteria so far. In situ hybridisation analysis of the CHD7 gene during early human development emphasised the role of CHD7 in the development of the central nervous system, internal ear, and neural crest of pharyngeal arches, and more generally showed a good correlation between specific CHD7 expression pattern and the developmental anomalies observed in CHARGE syndrome. CONCLUSIONS: These results allowed us to further refine the phenotypic spectrum of developmental anomalies resulting from CHD7 dysfunction.

Abnormalities, Multiple↗
PubMed2005

CHARGE syndrome includes hypogonadotropic hypogonadism and abnormal olfactory bulb development.

CONTEXT: CHARGE (coloboma, heart defect, choanal atresia, retarded growth and development, genital hypoplasia, ear abnormalities, and/or hearing loss defect) syndrome consists of a combination of congenital malformations including genital hypoplasia and retarded growth. OBJECTIVE: The objective of the study was to study gonadotropic axis function and growth parameters in CHARGE syndrome. DESIGN: This was a retrospective study. PATIENTS: The study included 32 children with CHARGE syndrome. RESULTS: Nineteen of 20 affected boys had micropenis and/or cryptorchidism, consistent with hypogonadotropic hypogonadism during fetal life. None of the boys was of pubertal age. Seven of nine boys tested before the age of 5 months during the neonatal peak period had extremely low testosterone levels. LH response to GnRH stimulation was variable during the first year of life and not correlated with existing clinical abnormalities. None of the girls over the age of 12 yr (n = 7) had begun puberty spontaneously, and a lack of response to GnRH stimulation was documented in five of them. Olfactory evaluation (n = 10) and magnetic resonance imaging (n = 18) of the forebrain revealed defective sense of smell and abnormal olfactory bulbs in all cases. Cardiorespiratory and nutritional problems were corrected, but the mean height of the 25 children who had reached 5 yr of age was -2 +/- 0.2 sd score. Height was not correlated with birth length or body mass index. GH deficiency was diagnosed in only three children. CONCLUSION: These findings suggest that CHARGE syndrome includes the main features of Kallmann syndrome, which is defined by hypogonadotropic hypogonadism combined with a defective sense of smell and abnormal olfactory bulb development. This forebrain abnormality, if confirmed in a larger group of patients, could serve as a major new criterion for the diagnosis of CHARGE syndrome.

Body Mass Index↗
PubMed2005

[Role of the combination of external radiotherapy--partial cystectomy--interstitial brachytherapy in pT1 G3, pT2 and pT3 bladder tumors].

Although it is still the reference method for curative treatment of invasive bladder cancer, radical cystectomy is a major surgical procedure justifying the evaluation of surgical tumoral excision in combination with curietherapy. At Nice University Hospital, between 1986 and 1998, 29 men with invasive bladder cancer were treated by partial cystectomy and interstitial brachytherapy. All the patients received external preoperative radiation of the pelvis of 10.5 Gy (Three 3.5 Gy flashes) three days before partial cystectomy associated with implantation of curietherapy guides carried out on average Five days after surgery with the dose of 50 Gy. After between 5 to 17 years of follow-up, eight deaths out of 14 occurred due to the disease and/or treatment, three patients had a superficial recurrence and one patient underwent salvage prostatocystectomy. Curietherapy gave rise to no direct complications, three patients suffered an eventration and 1 evisceration. Two out of 15 surviving patients suffer from invalidating pollakiuria and one from chronic retention. This study shows that overall survival corrected for intercurrent deaths is lower than data in the literature, though the low sample size makes it impossible to compare the carcinological results and survival per pT category. In addition, this strategy results in fewer complications after radiation therapy. Hence, although a certain number of questions remain unanswered, it seems possible for suitably selected patients to expect the same cure rates as radical surgery with reduced morbidity.

Adult↗
PubMed2004

Atypical findings in Kabuki syndrome: report of 8 patients in a series of 20 and review of the literature.

Kabuki syndrome (KS) is a rare multiple congenital anomaly/mental retardation syndrome with an estimated frequency of 1/32,000 in Japan. Five major criteria delineate KS namely postnatal short stature, skeletal anomalies, moderate mental retardation, dermatoglyphic anomalies, and a characteristic facial dysmorphism. Here we report on a series of 20 sporadic KS patients and we focus on some rare and atypical features that we have observed: chronic and/or severe diarrhea (4/20) including celiac disease, diaphragmatic defects (3/20), pseudarthrosis of the clavicles (2/20), vitiligo (2/20), and persistent hypoglycemia (2/20). Other occasional findings were severe autoimmune thrombopenia, cerebellar vermis atrophy, and myopathic features. Interestingly, one of our KS patients presented with a clinical overlap with CHARGE syndrome (right eye microphtalmia with optic nerve coloboma, VSD, bilateral cryptorchidism, and severe deafness). Because these features are more frequent in our series than previously described, we propose to carefully investigate these manifestations during KS patient survey in an attempt to determine their real frequency and in order to improve clinical management.

Abnormalities, Multiple↗
PubMed2004

[Potential sexual consequences associated with benign prostatic hyperplasia and its treatments].

In this article, an updated review of the potential consequences of treatment of benign prostatic hyperplasia (BPH) on sexual function is proposed in the light of recent data. Differences exist between the different therapeutic options available for the treatment of lower urinary tract symptoms (LUTS) when we want to analyze the impact on sexuality. Surgical procedures including minimally invasive techniques are associated with ejaculation and also erection disorders. Drug treatments also have repercussions on sexuality though there are significant differences between the various classes of these drugs. In daily practice, the relation between the prostate and sexuality must be assessed during any medical examination for one of these diseases and before any decision on treatment.

Humans↗
PubMed2004

Genome-wide screening using automated fluorescent genotyping to detect cryptic cytogenetic abnormalities in children with idiopathic syndromic mental retardation.

Mental retardation (MR) is the most common developmental disability, affecting approximately 2% of the population. The causes of MR are diverse and poorly understood, but chromosomal rearrangements account for 4-28% of cases, and duplications/deletions smaller than 5 Mb are known to cause syndromic MR. We have previously developed a strategy based on automated fluorescent microsatellite genotyping to test for telomere integrity. This strategy detected about 10% of cryptic subtelomeric rearrangements in patients with idiopathic syndromic MR. Because telomere screening is a first step toward the goal of analyzing the entire genome for chromosomal rearrangements in MR, we have extended our strategy to 400 markers evenly distributed along the chromosomes to detect interstitial anomalies. Among 97 individuals tested, three anomalies were found: two deletions (one in three siblings) and one parental disomy. These results emphasize the value of a genome-wide microsatellite scan for the detection of interstitial aberrations and demonstrate that automated genotyping is a sensitive method that not only detects small interstitial rearrangements and their parental origin but also provides a unique opportunity to detect uniparental disomies. This study will hopefully contribute to the delineation of new contiguous gene syndromes and the identification of new imprinted regions.

Child↗
PubMed2004

A weekly schedule of docetaxel for metastatic hormone-refractory prostate cancer.

RATIONALE: Docetaxel has proven its efficacy in the management of hormone-refractory prostate cancer (HRPC). Schedules of docetaxel administration differ. This prospective phase II study was designed to reevaluate the activity and toxicity of docetaxel administered weekly at an optimal dose to a large cohort of HRPC patients. PATIENTS AND METHODS: Sixty-four patients were treated with docetaxel 40 mg/m(2) i.v., administered weekly for 6 consecutive weeks followed by a 2-week recovery period. Three treatment cycles were planned in the absence of progression or toxicity. The principal end point was the biochemical response based on the prostate-specific antigen (PSA) level (a decline of more than 50% for at least 4 weeks). Secondary end points were objective response to measurable disease, survival and toxicity. RESULTS: Toxicity was assessed in 64 patients. Toxicity was acceptable, with no toxicity-related deaths. Twenty-one percent of the patients developed grade 3-4 hematological toxicity. Sixty-four patients were evaluable for the PSA response. Forty-one patients (64%) achieved a decrease in PSA of >50%, 13 of whom had a PSA <4 ng/ml. Two out of 12 patients with measurable disease exhibited an objective response. With respect to PSA, the median progression-free survival was 29 weeks (95% confidence interval: 18-46 weeks). The global 1-year survival rate was 58%. CONCLUSION: Weekly docetaxel at a dosage of 40 mg/m(2) is a well-tolerated treatment, which has very promising activity on the reduction of PSA in metastatic HRPC. A large phase III study is underway.

Aged↗
PubMed2004

[Percutaneous nephrolithotomy (PCNL) in subjects over the age of 70: a multicentre retrospective study of 210 cases].

INTRODUCTION: Percutaneous nephrolithotomy (PCNL) in subjects over the age of 70 is considered to be associated with a higher risk than extracorporeal shock-wave lithotripsy (ESWL). However this technique is sometimes necessary for very large or complex stones in patients with several comorbidities. STUDY OBJECTIVE: To evaluate the predictive factors of success and operative risks likely to influence the results of PCNL in a population of patients over the age of 70. MATERIAL AND METHOD: Retrospective study of 203 patients (110 males, 97 females) over the age of 70, in whom a total of 210 PCNL were performed over a 12-year period in ten referral centres for the treatment of stones. 68.5% of cases presented a comorbidity and the median ASA score was 2. The median stone dimensions were 24 x 15 mm. There were 67 solitary pelvic stones, 7 infrapelvic ureteric stones, 31 solitary inferior caliceal stones, 40 complex stones and 13 staghorn calculi. A standard one-stage operative technique was performed in 92% of cases; the nephrostomy tract was easily performed by the urologists themselves in 71.8% of cases. RESULTS: The overall stone-free (SF) rate was 70.8%. The patient's weight and height (p=0.03 and p=0.01), stone dimensions and their solitary nature were significant factors of success (p<0.00001 and p=0.01) with SF rates of 81.1% for pelvic stones and 90.3%for solitary inferior caliceal stones (p<0.003); the SF rate for complete staghorn calculi was only 30.8%. A history of stones (p=0.04) and diabetes (p=0.03) influenced the stone-free rate, but the other comorbidities, body mass index, and age did not influence the stone-free rate. There were two deaths (0.9% and haemostasis nephrectomy was performed in 2 ASA 3 subjects in renal failure. In the other patients, there was no difference between preoperative and postoperative serum creatinine and haemoglobin levels. The ease of nephrostomy, the rapidity of PCNL, the day of removal of the drainage nephrostomy, the mean hospital stay (median stay: 6 days), sterility of postoperative urine and at the 1-month visit were significantly correlated with the SF rate. CONCLUSIONS: PCNL in subjects over the age of 70 years is a safe and reliable technique that achieved a stone-free rate of 70.8% for all types of stones combined. The best results were obtained for solitary stones larger than 20 mm in the renal pelvis or inferior calyx. Apart from diabetes, which remains a risk factor, well controlled comorbidities do not increase the operative risk. PCNL did not affect haemodynamic parameters or renal function.

Age Factors↗
PubMed2003

PMX2B, a new candidate gene for Hirschsprung's disease.

Hirschsprung's (HSCR) disease is a congenital intestinal malformation of the enteric nervous system. It is a multigenic malformation and until now, eight genes have been involved in the etiology of this disease: genes encoding proteins of the RET signaling pathway (RET, GDNF and NTN), genes participating in the endothelin (EDN) type B receptor pathway (EDNRB, EDN3 and ECE-1), the SOX10 gene and the SIP1 gene that is mutated in syndromic forms of HSCR. Mutations of these genes are found in not more than 50-60% of affected individuals. Here, we report on the results of a molecular cytogenetic study performed in a girl who presented with a syndromic short segment HSCR associated with a de novo t(4;8)(p13;p22) translocation. A comparative genomic hybridization (CGH) study found a 4p12p13 deletion. A molecular characterization of this rearrangement showed that the 4p13 deletion was 5 Mb in length and included the paired mesoderm homeobox gene (PMX2B) (MIM 603851), a gene expressed in the human embryonic gut and essential for the development of autonomic neural crest derivatives. The present observation suggests that PMX2B haploinsuffciency might predispose to HSCR.

Abnormalities, Multiple↗
PubMed2003

Frameshift mutation of the zinc finger homeo box 1 B gene in syndromic corpus callosum agenesis (Mowat-Wilson syndrome).

We report a girl who had Hirschsprung disease in association with distinct facial appearance, microcephaly, agenesis of the corpus callosum and mental retardation (Mowat-Wilson syndrome). Mutation analysis of the zinc finger homeo box 1 B (ZFHX1 B) gene revealed a de novo 7 bp deletion (TGGCCCC) at nucleotide 1773 (1773 delTGGCCCC) resulting in a frameshift and leading to a termination codon at amino acid residue 604 (604 X) in exon 8 C. The zinc finger homeo box 1 B (Smad interacting protein-1) is a transcription corepressor of Smad target genes with functions in the patterning of neural crest derived cells, CNS, and midline structures. Mutations in ZFHX1 B can lead to neurological disorders in addition to dysmorphic features, megacolon, and other malformations.

Abnormalities, Multiple↗
PubMed2003

Spectrum of NSD1 mutations in Sotos and Weaver syndromes.

Sotos syndrome is an overgrowth syndrome characterised by pre- and postnatal overgrowth, macrocephaly, advanced bone age, and typical facial features. Weaver syndrome is a closely related condition characterised by a distinctive craniofacial appearance, advanced carpal maturation, widened distal long bones, and camptodactyly. Haploinsufficiency of the NSD1 gene has recently been reported as the major cause of Sotos syndrome while point mutations accounted for a minority of cases. We looked for NSD1 deletions or mutations in 39 patients with childhood overgrowth. The series included typical Sotos patients (23/39), Sotos-like patients (lacking one major criteria, 10/39), and Weaver patients (6/39). We identified NSD1 deletions (6/33) and intragenic mutations (16/33) in Sotos syndrome patients. We also identified NSD1 intragenic mutations in 3/6 Weaver patients. We conclude therefore that NSD1 mutations account for most cases of Sotos syndrome and a significant number of Weaver syndrome cases in our series. Interestingly, mental retardation was consistently more severe in patients with NSD1 deletions. Macrocephaly and facial gestalt but not overgrowth and advanced bone age were consistently observed in Sotos syndrome patients. We suggest therefore considering macrocephaly and facial gestalt as mandatory criteria for the diagnosis of Sotos syndrome and overgrowth and advanced bone age as minor criteria.

Abnormalities, Multiple↗
PubMed2002

Prenatal diagnosis of a lethal form of Netherton syndrome by SPINK5 mutation analysis.

Netherton syndrome (NS) is a severe autosomal recessive ichthyosis with no specific treatment or prenatal diagnosis available at present. The recent identification of SPINK5, which encodes a serine protease inhibitor, as the defective gene enables DNA based prenatal diagnosis to be carried out. Here we report the first direct molecular prenatal diagnosis of a lethal form due to a recurrent SPINK5 mutation in three consanguineous Turkish families. XmnI restriction enzyme digestion and DNA sequencing demonstrated that each deceased affected child was homozygous for mutation 153delT inherited from each parent. Analysis of fetal DNA from amniotic fluid cells in Family 1 and from a chorionic villus sampling in Family 3 showed that the fetus was heterozygous for 153delT in both cases. The pregnancies were carried to term and the newborns were unaffected. In Family 2, fetal DNA analysis from chorionic villus biopsy showed in a first pregnancy that the fetus was homozygous for 153delT. The pregnancy was terminated at 13 weeks and DNA analysis of fetal keratinocytes confirmed the prenatal prediction. In a second pregnancy in Family 2, fetal DNA analysis showed heterozygosity for 153delT, and the pregnancy was continued. Direct SPINK5 mutation analysis in families at risk for NS represents the first early, rapid and reliable method for prenatal diagnosis of this life threatening form of ichthyosis.

Amniocentesis↗