Search

Branchio-oto-renal (BOR) syndrome is an autosomal dominant disorder characterized by branchial, ear, and renal anomalies. Over 80 mutations in EYA1 have been reported in BOR. Mutations in SIX1, a DNA binding protein that associates with EYA1, have been reported less frequently. One group has recently described four missense mutations in SIX5 in five unrelated patients with BOR. Here, we report a screening of these three genes in a cohort of 140 patients from 124 families with BOR. We identified 36 EYA1 mutations in 42 unrelated patients, 2 mutations, and 1 change of unknown significance in SIX1 in 3 unrelated patients, but no mutation in SIX5. We did not find correlation between genotype and phenotype, and observed a high phenotypic variability between and within BOR families. We show the difficulty in establishing a molecular diagnosis strategy in BOR syndrome: the screening focusing on patients with typical BOR would detect a mutation rate of 76%, but would also miss mutations in 9% of patients with atypical BOR. We detected a deletion removing three EYA1 exons in a patient who was previously reported to carry the SIX5 Thr552Met mutation. This led us to reconsider the role of SIX5 in the development of BOR., (© 2011 Wiley-Liss, Inc.)

This article focuses on six questions raised by genetic testing in human: (1) the use of genetic tests, (2) information given to relatives of patients affected with genetic disorders, (3) prenatal and preimplantatory diagnosis for late onset genetic diseases and the use of pangenomic tests in prenatal diagnosis, (4) direct-to-consumer genetic testing, (5) population screening in the age of genomic medicine and (6) incidental findings when genetic testing are used., (Copyright © 2009 Elsevier Masson SAS. All rights reserved.)

Objective: To investigate the implication of SLC26A4, FOXI and KCNJ10 genes in unilateral hearing impairment associated with ipsilateral inner ear malformation (Enlargement of the vestibular aqueduct and/or Mondini dysplasia)., Methods: We have gathered 25 patients presenting unilateral hearing impairment and ipsilateral enlarged vestibular aqueduct. For each of the patients, we have analyzed SLC26A4, FOXI1 and KCNJ10 genes sequences., Results: The analysis of SLC26A4 revealed only eight heterozygous SLC26A4 sequence variants, three of them being novel (p.Met147Ile, p.Asn538Asn and p.Leu627Arg). None of the patients carried a second mutation on the other allele. Moreover, the SLC26A4 locus was excluded by segregation analysis in two families. No mutations were present in FOXI1 and KCNJ10 genes., Conclusions: Together, these data suggest that SLC26A4, FOXI1 and KCNJ10 are not major determinants in unilateral deafness and enlarged vestibular aqueduct compared with their implication in Pendred syndrome and non-syndromic bilateral enlarged vestibular aqueduct., (Copyright 2010 Elsevier Ireland Ltd. All rights reserved.)

Oculoauriculovertebral spectrum (OAVS) is a clinically and genetically heterogeneous congenital disorder. We performed high density oligonucleotide array-CGH on 86 OAVS patients and identified in 11 patients 12 novel genomic rearrangements (4 deletions and 8 duplications) ranging in size from 2.7 kb to 2.3 Mb. We discuss the potential pathogenic role of these chromosomal aberrations, and describe new candidate regions for OAVS.

Cerebral, ocular, dental, auricular, skeletal syndrome (CODAS, OMIM 600373) is a very rare congenital malformation syndrome. This clinical entity is highly distinctive and associates mental retardation, cataract, enamel abnormalities, malformations of the helix, epiphyseal and vertebral malformations, and characteristic dysmorphic features. Since 1991, only three affected children have been reported. The etiology and pattern of inheritance of CODAS syndrome still remain unknown. We describe a new sporadic case presenting with all the characteristic features of CODAS syndrome associated with previously unreported malformations of the heart, larynx, and liver. All investigations such as karyotype, metabolic screening and array CGH were normal., ((c) 2010 Wiley-Liss, Inc.)

Transient deafness associated with an increase in core body temperature is a rare and puzzling disorder. Temperature-dependent deafness has been previously observed in patients suffering from auditory neuropathy. Auditory neuropathy is a clinical entity of sensorineural deafness characterized by absent auditory brainstem response and normal otoacoustic emissions. Mutations in OTOF, which encodes otoferlin, have been previously reported to cause DFNB9, a non-syndromic form of deafness characterized by severe to profound prelingual hearing impairment and auditory neuropathy. Here we report a novel mutation in OTOF gene in a large family affected by temperature-dependent auditory neuropathy. Three siblings aged 10, 9 and 7 years from a consanguineous family were found to be affected by severe or profound hearing impairment that was only present when they were febrile. The non-febrile patients had only mild if any hearing impairment. Electrophysiological tests revealed auditory neuropathy. Mapping with microsatellite markers revealed a compatible linkage in the DFNB9/OTOF region in the family, prompting us to run a molecular analysis of the 48 exons and of the OTOF intron-exon boundaries. This study revealed a novel mutation p.Glu1804del in exon 44 of OTOF. The mutation was found to be homozygous in the three patients and segregated with the hearing impairment within the family. The deletion affects an amino acid that is conserved in mammalian otoferlin sequences and located in the calcium-binding domain C2F of the protein., (Copyright 2010 Elsevier Inc. All rights reserved.)

Waardenburg syndrome (WS) is characterized by the association of pigmentation abnormalities, including depigmented patches of the skin and hair, vivid blue eyes or heterochromia irides, and sensorineural hearing loss. However, other features such as dystopia canthorum, musculoskeletal abnormalities of the limbs, Hirschsprung disease, or neurological defects are found in subsets of patients and used for the clinical classification of WS. Six genes are involved in this syndrome: PAX3 (encoding the paired box 3 transcription factor), MITF (microphthalmia-associated transcription factor), EDN3 (endothelin 3), EDNRB (endothelin receptor type B), SOX10 (encoding the Sry bOX10 transcription factor), and SNAI2 (snail homolog 2), with different frequencies. In this review we provide an update on all WS genes and set up mutation databases, summarize molecular and functional data available for each of them, and discuss the applications in diagnostics and genetic counseling., ((c) 2010 Wiley-Liss, Inc.)

Objective: To gain insight into the pathophysiology of an atypical familial form of an autoinflammatory disorder, characterized by autosomal-dominant sensorineural hearing loss, systemic inflammation, increased secretion of interleukin-1beta (IL-1beta), and the absence of any cutaneous manifestations, and to assess the functional consequences of a missense mutation identified in the leucine-rich repeat (LRR) domain of NLRP3., Methods: Microsatellite markers were used to test the familial segregation of the NLRP3 locus with the disease phenotype. All NLRP3 exons were screened for mutations by sequencing. Functional assays were performed in HEK 293T cells to determine the effects of mutated (versus normal) NLRP3 proteins on NF-kappaB activation, caspase 1 signaling, and speck formation., Results: A heterozygous NLRP3 missense mutation (p.Tyr859Cys) was identified in exon 6, which encodes the LRR domain of the protein. This mutation was found to segregate with the disease phenotype within the family, and had a moderate activating effect on speck formation and procaspase 1 processing and did not alter the inhibitory properties of NLRP3 on NF-kappaB signaling., Conclusion: This report is the first to describe a familial form of a cryopyrinopathy associated with a mutation outside of exon 3 of NLRP3. This finding, together with the known efficacy of anti-IL-1 treatments in these disorders, underlines the importance of screening all exons of NLRP3 in patients who present with atypical manifestations. In addition, the gain of function associated with this mutation in terms of activation of caspase 1 signaling was consistent with the observed inflammatory phenotype. Therefore, this study of the functional consequences of an LRR mutation sheds new light on the clinical relevance of in vitro assays.

X-linked deafness is a rare cause of hereditary isolated hearing impairment estimated as at least 1% or 2% of the non-syndromic hearing loss. To date, four loci for DFN have been identified and only one gene, POU3F4 responsible for DFN3, has been cloned. In males, DFN3 is characterized by a progressive deafness associated with perilymphatic gusher at stapes surgery and with a characteristic inner ear malformation. The phenotype of eight independent females carrying POU3F4 anomalies is defined, and a late-onset hearing loss is found in three patients. Only one has an inner ear malformation. No genotype/phenotype correlation is identified.

Background: Usher syndrome type 1 needs to be diagnosed at early age in order to timely manage speech therapy, cochlear implantation, and genetic counseling. Few data are available regarding electroretinographic testing before the age of six years., Aim: To describe electroretinographic changes in young children with Usher syndrome type 1., Methods: Retrospective study of fourteen patients. Age at first neurophysiologic testing was between 17 months and 5 years 4 months. Electroretinogram was performed using flash stimulation in mesopic conditions in the conscious child. Analysis was focused on the amplitudes and latencies of a- and b-waves., Results: Whatever the age, an abnormal fundus was always confirmed with an absent electroretinogram. The youngest patient with absent electroretinogram was 17 month-old. When recorded on and after the 29th month of age, electroretinogram was absent in all cases, including 6 patients with normal fundus. In three patients a low-amplitude electroretinogram was present at first recording within the 26th and 27th months., Conclusion: Electroretinogram showed retinopathy in young children with Usher syndrome type 1, even in the absence of fundoscopic signs of retinal degeneration.

Cogan's syndrome is a rare chronic inflammatory disorder which typically associates an ophthalmological and vestibulocochlear involvement, with a risk of systemic symptoms in 50-70% of cases. Autoimmune origin has been consolidated by the recent discoveries of Lunardi as a result of the dysregulation of the response of B and T lymphocytes. We report here a pediatric case of Cogan's syndrome, with long term follow-up and complete vestibulocochlear and ophthalmologic examination. During the acute phase, early steroids treatment (prednisone 1mg/kg per day) was effective on ocular lesions and hearing loss. The patient required high steroid doses to maintain remission, suggesting the necessity for steroid sparing immunosuppressive agents. We introduced mycophenolate mofetil (MMF), an immunosuppressive agent mainly used in solid organ transplantation. After steroid withdrawal the patient remained in complete remission on MMF. This is the first report of MMF treatment in Cogan's syndrome. MMF produces a targeted inhibition of the proliferation of B and T lymphocytes, particularly interesting in Cogan's syndrome. Low long term toxicity and overall good tolerance make MMF a new treatment option in steroid dependent Cogan's syndrome.

Mutations in the GJB2 gene encoding the gap junction protein connexin 26 are responsible for up to 30% of all cases of autosomal recessive nonsyndromic hearing impairment (HI) with prelingual onset in most populations. The corresponding locus DFNB1, located on chromosome 13q11-q12, is also affected by three distinct deletions. These deletions extended distally to GJB2, which remains intact. We report a novel large deletion in DFNB1 observed in a patient presenting profound prelingual HI. This deletion was observed in trans to a GJB2 mutated allele carrying the p.Val84Met (V84M) mutation and was shown to be associated with hearing loss. The deletion caused a false homozygosity of V84M in the proband. Quantification of alleles by quantitative fluorescent multiplex PCR (QFM-PCR) enabled us to study the breakpoints of the deletion. The deleted segment extended through at least 920kb and removed the three connexin genes GJA3, GJB2 and GJB6. The distal breakpoint inside intron 2 of CRYL1 gene differed from the breakpoints of the known DFNB1 deletions. This case highlights the importance of screening for large deletions in molecular studies of GJB2.

Objective: To evaluate the results of velopharyngoplasty for velopharyngeal insufficiency (VPI) in relation to 22q11 deletion or nonsyndromic VPI., Design: Retrospective study., Setting: Academic medical center., Patients: Eleven of 45 patients with 22q11 microdeletion (group 1) and 9 patients without 22q11 microdeletion (group 2) with noncleft VPI (hypoplastic velum or hypodynamic velopharynx and deep pharynx) underwent velopharyngoplasty (midline pharyngeal flap with superior pedicle). Exclusion criteria included cleft palate, submucous cleft palate, all syndromic cases, and all associated malformations (except those related to 22q11 microdeletion in patients with DiGeorge syndrome)., Main Outcome Measures: Speech assessment before surgery using the Borel-Maisonny scale and at 9 months and 24 months after surgery. Velopharyngeal insufficiency was classified as normal, inconsistent, mild, moderate, and severe., Results: Before surgery, in group 1, 3 patients had mild and 8 had severe VPI, and in group 2, 1 had mild and 8 had severe VPI. Postoperative outcomes at 9 months showed that in group 1, 2 patients had excellent results (normal and inconsistent) and 9 had mild VPI, while in group 2, 6 patients had excellent results and 3 had mild VPI (P = .03). Postoperative outcomes at 24 months showed that in group 1, 10 patients had excellent results and 1 had mild VPI, while in group 2, 8 patients had excellent results and 1 had mild VPI., Conclusions: Surgical treatment of noncleft VPI by pharyngoplasty was efficient in 10 of the 11 patients (91%) in the 22q11 group and in 8 of the 9 patients (89%) in the nonsyndromic group. Postoperative remission took longer for patients with the 22q11 microdeletion than for the control group. However, long-term results following surgical treatment were equally good in the 2 groups.

Hereditary hearing loss (HL) is a very heterogeneous trait, with 46 gene identifications for non-syndromic HL. Mutations in GJB2 cause up to half of all cases of severe-to-profound congenital autosomal recessive non-syndromic HL, with 35delG being the most frequent mutation in Caucasians. Although a genotype-phenotype correlation has been established for most GJB2 genotypes, the HL of 35delG homozygous patients is mild to profound. We hypothesise that this phenotypic variability is at least partly caused by the influence of modifier genes. By performing a whole-genome association (WGA) study on 35delG homozygotes, we sought to identify modifier genes. The association study was performed by comparing the genotypes of mild/moderate cases and profound cases. The first analysis included a pooling-based WGA study of a first set of 255 samples by using both the Illumina 550K and Affymetrix 500K chips. This analysis resulted in a ranking of all analysed single-nucleotide polymorphisms (SNPs) according to their P-values. The top 250 most significantly associated SNPs were genotyped individually in the same sample set. All 192 SNPs that still had significant P-values were genotyped in a second independent set of 297 samples for replication. The significant P-values were replicated in nine SNPs, with combined P-values between 3 x 10(-3) and 1 x 10(-4). This study suggests that the phenotypic variability in 35delG homozygous patients cannot be explained by the effect of one major modifier gene. Significantly associated SNPs may reflect a small modifying effect on the phenotype. Increasing the power of the study will be of greatest importance to confirm these results.

We report two patients considered to have an atypical presentation of Hallerman-Streiff syndrome (HSS) associated with laterality and cardiac defects. Clinical features include typical facial gestalt, atrophy of the skin, and hypotrichosis. Ophthalmologic abnormalities, normally present in HSS, are only found in one of the two patients. Both of them have respiratory problems secondary to the classical narrow upper airway described in this syndrome. Both these patients have laterality defects and one has additional structural cardiac malformations. Cardiac defects have occasionally been reported in the HSS literature, but are not considered as a classical feature of the syndrome. Situs inversus has never been reported in this syndrome. Almost all HSS cases have been sporadic and their origin and inheritance pattern remain unknown.

The objective of this retrospective study is to evaluate the efficiency of hyperosmolar therapy for cerebrum spinal fluid (CSF) leakage in cochlear implant (CI) surgery in children with inner ear malformations. Between 1991 and 2006, 490 cochlear implantations were performed in Armand Trousseau Children's Hospital. Thirty-seven patients (7.5%) had inner ear malformation. They were classified as isolated enlargement of the vestibular aqueduct (EVA) (18 cases), incomplete partition (IP) (11 cases), common cavity (CC) (1 case) and variable canal and vestibular malformations (VSCC) (7 cases). A hyperosmolar protocol was applied during surgery to 13 patients after 2003 (Gp) to be compared to the 24 patients without treatment previously to this date (G0). Mean age at implant CI was 8.1 years (1-20 years), mean follow up was 3.9 years (1 month-15 years). Per operative observations were collected for all patients with an empiric method of evaluation of the leakage. A grading using five steps ranged from Grade 0 (no leak) to Grade 4 (gusher). Grading, complications and perceptive results in closed and open set word (Lafon lists) at respectively preoperatively, at 3 and 24 months were gathered and compared between the two groups. Important per operative leak was observed (Grade 4) in 24.3% cases (9/37) of Grade 4, 88.8% of them in G0 (8/9). In 66.6% cases there was a severe dysplasia (CC or IP) (6/9), to be compared to the 21.4% of cases of severe dysplasia with Grade<3 (6/28) (p=0.02). Grade 4 was seen in 45% cases of IP (5/11); it represented 33.3% of the IP in Gp (1/3), and 50% of the IP in G0 (4/8) (p>0.05). Grade 4 was seen in 16.6% cases of EVA (3/18); there were no Grade 4 observed in Gp (0/10), and 37.5% cases of EVA in G0 (3/8) (p=0.04). Grade 4 was observed in 100% case in CC in the G0 (1/1). Severe complications were misplacement of the electrode in one case (G0), persistent leakage in one case (G0) and meningitis in one case (Gp). Vertigo was observed in 29.7% of cases (11/37) in this population, 72.7% of them in G0 (8/11). Vertigo was associated to severe dysplasia in 75% cases in G0 (6/8), and to EVA in all cases in Gp. In G0, mean perceptive scores showed for G0, preoperatively and at 3 months, respectively, 1.3% and 50.6% in closed set word (CSW), and 65.9% in open set words at 2 years. In Gp mean perceptive scores showed preoperatively and at 3 months, respectively 6.1% and 69.8% in CSW, and 81% in open set words at 2 years. The differences between the two groups are not significant (p>0.05). Osmotherapy is known to be effective for cerebral oedema and regularly used in neurological surgery. In inner ear malformation, gusher at surgery is directly related to the intra-cerebral pressure (ICP). Corresponding to neurosurgical practice, the mainstay of our protocol rests on hyperosmolar treatment, to reduce the ICP the time of the surgery. Our results suggest that this treatment is effective for a better control of leakage at cochleostomy on EVA, and could be effective on more severe malformations. No severe complication related to surgery was seen in Gp. Its good tolerance could allow its use in most patients with inner ear malformation. Vertigo was a frequent complication. The possibility of vertigo depends on the initial vestibular status and on the course of the surgery. The protocol could protect the vestibular function, lowering the pressure and quantity of the liquid issue. The treatment does not seem to influence the perceptive results.

We report on two sporadic and two familial new cases with sensorineural hearing impairment and ovarian dysgenesis which are the cardinal signs of Perrault syndrome in females. Only one of them has a nervous system defect. We reviewed all the published cases of Perrault syndrome in order to define the clinical variability and to evaluate the frequency of the neurological anomalies in this clinical entity. Moreover we excluded GJB2, POLG, and FOXL2 as candidate genes in Perrault syndrome., ((c) 2008 Wiley-Liss, Inc.)

NALP proteins, also known as NLRPs, belong to the CATERPILLER protein family involved, like Toll-like receptors, in the recognition of microbial molecules and the subsequent activation of inflammatory and immune responses. Current advances in the function of NALPs support the recently proposed model of a disease continuum bridging autoimmune and autoinflammatory disorders. Among these diseases, hereditary periodic fevers (HPFs) are Mendelian disorders associated with sequence variations in very few genes; these variations are mostly missense mutations whose deleterious effect, which is particularly difficult to assess, is often questionable. The growing number of identified sporadic cases of periodic fever syndrome, together with the lack of discriminatory clinical criteria, has greatly hampered the identification of new disease-causing genes, a step that is, however, essential for appropriate management of these disorders. Using a candidate gene approach, we identified nonambiguous mutations in NALP12 (i.e., nonsense and splice site) in two families with periodic fever syndromes. As shown by means of functional studies, these two NALP12 mutations have a deleterious effect on NF-kappaB signaling. Overall, these data identify a group of HPFs defined by molecular defects in NALP12, opening up new ways to manage these disorders. The identification of these first NALP12 mutations in patients with autoinflammatory disorder also clearly demonstrates the crucial role of NALP12 in inflammatory signaling pathways, thereby assigning a precise function to this particular member of an emerging family of proteins whose putative biological properties are currently inferred essentially through in vitro means.

Keratitis-Ichthyosis-Deafness (KID) syndrome (OMIM 148210) is a congenital ectodermal defect. KID consists of an atypical ichthyosiform erythroderma associated with congenital sensorineural deafness. A rare form of the KID syndrome is a fatal course in the first year of life due to severe skin lesion infections and septicaemia. KID appears to be genetically heterogeneous and may be caused by mutations in connexin 26 or connexin 30 genes. GJB2 mutations in the connexin 26 gene are the main cause of the disease. Most of the cases caused by GJB2 mutations are sporadic, but dominant transmission has also been described. To date, the rare lethal form of the disease has been only observed in two Caucasian sporadic patients with the GJB2 mutation, with the p.Gly45Glu (G45E) arising de novo. We have reported an African family with dizygotic twins suffering from a lethal form of KID. The dizygosity of the twins was confirmed by microsatellite markers. The two patients were heterozygous for the G45E mutation of GJB2, whereas the mutation was not detected in the two parents. The unusual transmission of the disease observed in this family could be explained by the occurrence of a somatic or more probably a germinal mosaic in one of the parents.

Purpose: We conducted a multicenter, randomized trial to compare progression-free survival (PFS), overall survival (OS), and quality of life in women with metastatic breast cancer (MBC) receiving high-dose chemotherapy plus autologous stem-cell transplantation (ASCT; HDCT) compared with standard-dose therapy., Patient and Methods: Between April 1997 and December 2000, 386 women with MBC and no prior chemotherapy for metastatic disease were registered. After initial response to anthracycline- or taxane-based induction chemotherapy, 224 patients were randomly assigned: 112 to high-dose cyclophosphamide, mitoxantrone, and carboplatin chemotherapy and ASCT (HDCT), and 112 to standard therapy (ST). Median age was 47 years (range, 25 to 67 years). Thirty two percent of women randomly assigned had estrogen and progesterone receptor-negative breast cancer, 42% had visceral metastases, and 58% had bone metastases. Complete remission rates before random assignment were 11% for those receiving HDCT and 12% for those receiving ST., Results: After a median follow-up of 48 months, 79 deaths were observed in the HDCT arm and 77 deaths were observed in the ST arm; seven patients (6%) in the HDCT arm died as a result of toxicity. The median OS was 24 months for the HDCT arm (95% CI, 21 to 35 months) and 28 months for ST (95% CI, 22 to 33 months; hazard ratio [HR], 0.9; 95% CI, 0.6 to 1.2; P = .43). PFS was 11 months for HDCT and 9 months for ST (HR, 0.6 in favor of HDCT; 95% CI, 0.5 to 0.9; P = .006)., Conclusion: HDCT did not improve OS in women with MBC when used as consolidation after response to induction chemotherapy.

Waardenburg syndrome (WS) is an auditory-pigmentary disorder that exhibits varying combinations of sensorineural hearing loss and abnormal pigmentation of the hair and skin. Depending on additional symptoms, WS is classified into four subtypes, WS1-WS4. Absence of additional features characterizes WS2. The association of facial dysmorphic features defines WS1 and WS3, whereas the association with Hirschsprung disease (aganglionic megacolon) characterizes WS4, also called "Waardenburg-Hirschsprung disease." Mutations within the genes MITF and SNAI2 have been identified in WS2, whereas mutations of EDN3, EDNRB, and SOX10 have been observed in patients with WS4. However, not all cases are explained at the molecular level, which raises the possibility that other genes are involved or that some mutations within the known genes are not detected by commonly used genotyping methods. We used a combination of semiquantitative fluorescent multiplex polymerase chain reaction and fluorescent in situ hybridization to search for SOX10 heterozygous deletions. We describe the first characterization of SOX10 deletions in patients presenting with WS4. We also found SOX10 deletions in WS2 cases, making SOX10 a new gene of WS2. Interestingly, neurological phenotypes reminiscent of that observed in WS4 (PCWH syndrome [peripheral demyelinating neuropathy, central dysmyelinating leukodystrophy, WS, and Hirschsprung disease]) were observed in some WS2-affected patients with SOX10 deletions. This study further characterizes the molecular complexity and the close relationship that links the different subtypes of WS.

Mitochondrial DNA (mtDNA) mutations have been implicated in non-syndromic hearing loss either as primary or as predisposing factors. As only a part of the mitochondrial genome is usually explored in deafness, its prevalence is probably under-estimated. Among 1350 families with non-syndromic sensorineural hearing loss collected through a French collaborative network, we selected 29 large families with a clear maternal lineage and screened them for known mtDNA mutations in 12S rRNA, tRNASer(UCN) and tRNALeu(UUR) genes. When no mutation could be identified, a whole mitochondrial genome screening was performed, using a microarray resequencing chip: the MitoChip version 2.0 developed by Affymetrix Inc. Known mtDNA mutations was found in nine of the 29 families, which are described in the article: five with A1555G, two with the T7511C, one with 7472insC and one with A3243G mutation. In the remaining 20 families, the resequencing Mitochip detected 258 mitochondrial homoplasmic variants and 107 potentially heteroplasmic variants. Controls were made by direct sequencing on selected fragments and showed a high sensibility of the MitoChip but a low specificity, especially for heteroplasmic variations. An original analysis on the basis of species conservation, frequency and phylogenetic investigation was performed to select the more probably pathogenic variants. The entire genome analysis allowed us to identify five additional families with a putatively pathogenic mitochondrial variant: T669C, C1537T, G8078A, G12236A and G15077A. These results indicate that the new MitoChip platform is a rapid and valuable tool for identification of new mtDNA mutations in deafness.

We compared two protocols for extracting DNA from dried blood spots for cytomegalovirus (CMV) DNA detection and quantification by real-time PCR. Both extraction methods were reliable for the retrospective diagnosis of CMV congenital infection. Quantification of CMV DNA was valuable after normalization of viral loads with albumin gene PCR amplification results.

The phenotype of monosomy 18p varies widely, the main clinical manifestations being mental and growth retardation, and craniofacial dysmorphism. Clinical features also include growth hormone (GH) deficiency, or holoprosencephaly (HPE). Haploinsufficiency for TGIF, mapped to 18p11.3, is not generally sufficient to cause HPE. To perform a genotype-phenotype correlation, and delineate the region involved in GH deficiency, we carried out a molecular characterization of the 18p deletions, in three patients with midline defects. Two unrelated children, a 7-month-old girl and a 2-month-old boy had del(18p) syndrome and GH deficiency. In addition, the boy had HPE. HPE genes, SHH, ZIC2, SIX3, and TGIF, were tested by denaturing high-performance liquid chromatography and quantitative multiplex of PCR short fluorescent fragments analyses. A deletion of TGIF was confirmed, without any associated mutation for the tested HPE genes, suggesting the role of other genetic or environmental factors. The third patient was his moderately retarded mother. A set of chromosome 18p-specific BACs clones was used as fluorescence in-situ hybridization probes to define the breakpoints. Recently, it was found that there seem to be a breakpoint cluster in the centromeric region at 18p11.1, which was not observed in our patients. The girl was found to have a deletion of 10.3 Mb, with a breakpoint in 18p11.22. The boy and his mother had a smaller deletion (8 Mb), with a breakpoint in 18p11.23. These findings suggest that the distal region on 18p is involved in the main clinical features, and GH deficiency, in 18p deletions.

Background: Time-resolved fluorescence immunoassays (TR-FIAs) for phytoestrogens in biological samples are an alternative to mass spectrometric methods. These immunoassays were used to test urine and plasma samples from individuals in a dietary intervention trial aimed at determining the efficacy of dietary isoflavones in reducing the risk of coronary heart disease in postmenopausal women., Methods: We established murine monoclonal TR-FIA methods for daidzein, genistein, and equol. These assays could be performed manually or adapted to an automated analyzer for high throughput and increased accuracy. Analysis of urine was conducted on nonextracted samples. Blood analysis was performed on nonextracted samples for daidzein, whereas genistein and equol required diethyl-ether extraction., Results: Comparison of monoclonal TR-FIA, commercial polyclonal antibody-based TR-FIA, and gas chromatography-mass spectrometry showed correlations (r, 0.911-0.994) across the concentration range observed in the Isoheart study (50 mg/day isoflavones). The concentrations of urinary daidzein and genistein observed during intervention demonstrated good compliance, and a corresponding increase in serum daidzein and genistein confirmed bioavailability of the isoflavone-rich foods; 33 of the 117 volunteers (28.2%) were classified as equol producers on the basis of their urinary equol concentration (>936 nmol/L), and significant differences in the numbers of equol producers were observed between Berlin and the 3 other European cohorts studied., Conclusions: The validated monoclonal TR-FIA methods are applicable for use in large-scale human phytoestrogen intervention studies and can be used to monitor compliance, demonstrate bioavailability, and assess equol producer status.

Townes-Brocks syndrome (TBS) is an autosomal dominant malformation syndrome characterized by renal, anal, ear, and thumb anomalies caused by SALL1 mutations. To date, 36 SALL1 mutations have been described in TBS patients. All but three of those, namely p.R276X, p.S372X, and c.1404dupG, have been found only in single families thereby preventing phenotype-genotype correlations. Here we present 20 novel mutations (12 short deletions, five short duplications, three nonsense mutations) in 20 unrelated families. We delineate the phenotypes and report previously unknown ocular manifestations, i.e. congenital cataracts with unilateral microphthalmia. We show that 46 out of the now 56 SALL1 mutations are located between the coding regions for the glutamine-rich domain mediating SALL protein interactions and 65 bp 3' of the coding region for the first double zinc finger domain, narrowing the SALL1 mutational hotspot region to a stretch of 802 bp within exon 2. Of note, only two SALL1 mutations would result in truncated proteins without the glutamine-rich domain, one of which is reported here. The latter is associated with anal, ear, hand, and renal manifestations, indicating that the glutamine-rich domain is not required for typical TBS., ((c) 2006 Wiley-Liss, Inc.)

Sensorineural hearing loss is the most frequent sensory deficit of childhood and is of genetic origin in up to 75% of cases. It has been shown that mutations of the SLC26A4 (PDS) gene were involved in syndromic deafness characterized by congenital sensorineural hearing impairment and goitre (Pendred's syndrome), as well as in congenital isolated deafness (DFNB4). While the prevalence of SLC26A4 mutations in Pendred's syndrome is clearly established, it remains to be studied in large cohorts of patients with nonsyndromic deafness and detailed clinical informations. In this report, 109 patients from 100 unrelated families, aged from 1 to 32 years (median age: 10 years), with nonsyndromic deafness and enlarged vestibular aqueduct, were genotyped for SLC26A4 using DHPLC molecular screening and sequencing. In all, 91 allelic variants were observed in 100 unrelated families, of which 19 have never been reported. The prevalence of SLC26A4 mutations was 40% (40/100), with biallelic mutation in 24% (24/100), while six families were homozygous. All patients included in this series had documented deafness, associated with EVA and without any evidence of syndromic disease. Among patients with SLC26A4 biallelic mutations, deafness was more severe, fluctuated more than in patients with no mutation. In conclusion, the incidence of SLC26A4 mutations is high in patients with isolated deafness and enlarged vestibular aqueduct and could represent up to 4% of nonsyndromic hearing impairment. SLC26A4 could be the second most frequent gene implicated in nonsyndromic deafness after GJB2, in this Caucasian population.

Objective: The purpose of the study is to present the results of cochlear implantation in case of deafness involving mutations in the OTOF gene. This form of deafness is characterized by the presence of transient evoked otoacoustic emissions (TEOAE). In cases of profound deafness with preserved TEOAE, two main etiologies should be considered: either an auditory neuropathy (a retrocochlear lesion) or an endocochlear lesion. It is essential to differentiate these two entities with regards to therapy and screening., Patients: We report two children who presented with profound prelingual deafness, confirmed by the absence of detectable responses to auditory evoked potentials (AEP), associated with the presence of bilateral TEOAE. Genetic testing revealed mutations in OTOF, confirming DFNB9 deafness. Both patients have been successfully implanted (with a follow-up of 18 and 36 months, respectively)., Main Outcome Measures: Clinical (oral production, closed and open-set words and sentences list, meaningful auditory integration scale), audiometric evaluation (TEOAE, AEP) before and after implantation, and neural response telemetry (NRT)., Results: Both patients present a good quality of clinical responses and electrophysiological tests after implantation, indicating satisfactory functioning of the auditory nerve. This confirms the endocochlear origin of DFNB9 and suggests that these mutations in OTOF lead to functional alteration of inner hair cells., Conclusion: In the absence of a context of neurological syndrome, the combination of absent AEP and positive TEOAE should lead to a genetic screening for mutations in OTOF, in order to undertake the appropriate management.

Introduction: Primary ciliary dyskinesia (PCD) is a rare disease classically transmitted as an autosomal recessive trait and characterised by recurrent airway infections due to abnormal ciliary structure and function. To date, only two autosomal genes, DNAI1 and DNAH5 encoding axonemal dynein chains, have been shown to cause PCD with defective outer dynein arms. Here, we investigated one non-consanguineous family in which a woman with retinitis pigmentosa (RP) gave birth to two boys with a complex phenotype combining PCD, discovered in early childhood and characterised by partial dynein arm defects, and RP that occurred secondarily. The family history prompted us to search for an X linked gene that could account for both conditions., Results: We found perfect segregation of the disease phenotype with RP3 associated markers (Xp21.1). Analysis of the retinitis pigmentosa GTPase regulator gene (RPGR) located at this locus revealed a mutation (631&#95;IVS6+9del) in the two boys and their mother. As shown by study of RPGR transcripts expressed in nasal epithelial cells, this intragenic deletion, which leads to activation of a cryptic donor splice site, predicts a severely truncated protein., Conclusion: These data provide the first clear demonstration of X linked transmission of PCD. This unusual mode of inheritance of PCD in patients with particular phenotypic features (that is, partial dynein arm defects and association with RP), which should modify the current management of families affected by PCD or RP, unveils the importance of RPGR in the proper development of both respiratory ciliary structures and connecting cilia of photoreceptors.

Hearing impairment (HI) affects 1 in 650 newborns, which makes it the most common congenital sensory impairment. Despite extraordinary genetic heterogeneity, mutations in one gene, GJB2, which encodes the connexin 26 protein and is involved in inner ear homeostasis, are found in up to 50% of patients with autosomal recessive nonsyndromic hearing loss. Because of the high frequency of GJB2 mutations, mutation analysis of this gene is widely available as a diagnostic test. In this study, we assessed the association between genotype and degree of hearing loss in persons with HI and biallelic GJB2 mutations. We performed cross-sectional analyses of GJB2 genotype and audiometric data from 1,531 persons, from 16 different countries, with autosomal recessive, mild-to-profound nonsyndromic HI. The median age of all participants was 8 years; 90% of persons were within the age range of 0-26 years. Of the 83 different mutations identified, 47 were classified as nontruncating, and 36 as truncating. A total of 153 different genotypes were found, of which 56 were homozygous truncating (T/T), 30 were homozygous nontruncating (NT/NT), and 67 were compound heterozygous truncating/nontruncating (T/NT). The degree of HI associated with biallelic truncating mutations was significantly more severe than the HI associated with biallelic nontruncating mutations (P<.0001). The HI of 48 different genotypes was less severe than that of 35delG homozygotes. Several common mutations (M34T, V37I, and L90P) were associated with mild-to-moderate HI (median 25-40 dB). Two genotypes--35delG/R143W (median 105 dB) and 35delG/dela(GJB6-D13S1830) (median 108 dB)--had significantly more-severe HI than that of 35delG homozygotes.

Twenty-one patients, including our two cases, with variable clinical phenotype, ranging from mild learning disability to severe congenital malformations or overlapping features with DiGeorge/velocardiofacial syndromes (DG/VCFS), have been shown to have a chromosome duplication 22q11 of the region that is deleted in patients with DG/VCFS. The reported cases have been identified primarily by interphase FISH and could have escaped identification and been missed by routine cytogenetic analysis. Here we report on two inherited cases, referred to us, to rule out 22q11 microdeletion diagnosis of VCFS. The first patient was a 2-month-old girl, who presented with cleft palate, minor dysmorphic features including short palpebral fissures, widely spaced eyes, long fingers, and hearing loss. Her affected mother had mild mental retardation and learning disabilities. The second patient was a 7(1/2)-year-old boy with velopharyngeal insufficiency and mild developmental delay. He had a left preauricular tag, bifida uvula, bilateral fifth finger clinodactyly, and bilateral cryptorchidism. His facial features appeared mildly dysmorphic with hypertelorism, large nose, and micro/retrognathia. The affected father had mild mental retardation and had similar facial features. FISH analysis of interphase cells showed three TUPLE1-probe signals with two chromosome-specific identification probes in each cell. FISH analysis did not show the duplication on the initial testing of metaphase chromosomes. On review, band q11.2 was brighter on one chromosome 22 in some metaphase spreads. The paucity of reported cases of 22q11.2 microduplication likely reflects a combination of phenotypic diversity and the difficulty of diagnosis by FISH analysis on metaphase spreads. These findings illustrate the importance of scanning interphase nuclei when performing FISH analysis for any of the genomic disorders., (Copyright 2005 Wiley-Liss, Inc.)

Aims: The purpose of the study was to define boundaries between endocochlear hearing loss and auditory neuropathy in children with congenital profound hearing loss and positive otoacoustic emissions., Patient: A child presented with bilateral profound hearing loss, which was confirmed by the absence of evoked auditory potentials at 110 dB and with conserved otoacoustic emissions. The lack of any relevant medical history, a normal neurologic pediatric examination, and the improvement obtained with powerful hearing aids suggested an endocochlear cause. Genetic testing identified mutations in OTOF, responsible for the DFNB9 recessive form of hearing loss., Results: In recent years, cases of children with hearing loss associated with positive otoacoustic emissions have been labeled as "auditory neuropathy." Classically, this form of hearing loss is refractory to the use of hearing aids and cochlear implants. Mutations in OTOF lead to inner hair cells dysfunction, whereas the outer hair cells are initially functionally preserved. As this form of endocochlear hearing loss can be detected at a molecular level, genetic testing can be proposed for cases of nonsyndromic auditory neuropathy, as those children could benefit from cochlear implantation., Conclusion: It is advisable to reserve the term "auditory neuropathy" for patients who present hearing loss and conserved otoacoustic emissions in the context of a neurologic syndrome or for children with suggestive perinatal history. In other cases, genetic testing for mutations in OTOF should be carried out.

Objective: To evaluate surgical aspects and results of cochlear implantation in inner ear malformations., Study Design: Retrospective cohort study., Setting: Ear, nose, and throat department of a tertiary referral hospital., Patients: Out of 260 implanted children, 18 (6.9%) had inner ear malformations: complex cochleovestibular malformation (n = 11), common cavity (n = 1), and enlarged vestibular aqueduct (EVA) (n = 6). Deafness was progressive in 12 cases (G1) and congenital in 6 cases (G2). Genetics lead to diagnosis in 12 of 13 cases: PSD mutation (n = 11), Waardenburg syndrome (n = 1), negative (1). Mean age at implant was 7.8 years. Mean follow-up period was 48 months., Main Outcome Measures: Medical and surgical outcomes were reported. Closed (CSW) and open (OSW) set word perception and level of speech production were evaluated each year. The results were compared pre- and postoperatively and between the two groups., Results: Gusher at surgery was observed in 50% of cases, with a persistent leak in one case. No facial injury or infectious complications were observed. At 12 months, 83% of the population had achieved more than 75% recognition in CSW, versus 16% before implant (p = 0.001). After 2 years, 64% of patients had more than 50% recognition in OSW. Good oral language was seen in 76% at 2 years and 100% at 3 years, versus 55% before implant (respectively, p > 0.05 and p = 0.03). At 1 year after implant, 83% of the G1 and 20% of the G2 achieved more than 50% recognition in OSW (p = 0.02). After 24 months, 83% of G1 and 40% of G2 had more than 50% in OSW (p > 0.05). Before implant, 75% in G1 and 0% in G2 had good oral language (p = 0.01). At 1 year, 83% in G1 and 16% in G2 had good oral language (p = 0.02). At 2 years, 100% in G1 and 20% in G2 had good oral language (p = 0.02). One child in G1 had no improvement after implantation., Conclusions: No major complication was seen. Perceptive and linguistic results were variable and depended on the type of the deafness. In progressive deafness, the perceptive and linguistic result are expected to be good. In congenital deafness, the results are more variable.

Objectives: To analyze the clinical features of hearing impairment and to search for correlations with the genotype in patients with DFNB1., Design: Case series., Setting: Collaborative study in referral centers, institutional practice. Patients A total of 256 hearing-impaired patients selected on the basis of the presence of biallelic mutations in GJB2 or the association of 1 GJB2 mutation with the GJB6 deletion (GJB6-D13S1830)del., Main Outcome Measures: The prevalence of GJB2 mutations and the GJB6 deletion and audiometric phenotypes related to the most frequent genotypes., Results: Twenty-nine different GJB2 mutations were identified. Allelic frequency of 35delG was 69%, and the other common mutations, 313del14, E47X, Q57X, and L90P, accounted for 2.6% to 2.9% of the variants. Concerning GJB6, (GJB6-D13S1830)del accounted for 5% of all mutated alleles and was observed in 25 of 93 compound heterozygous patients. Three novel GJB2 mutations, 355del9, V95M, and 573delCA, were identified. Hearing impairment was frequently less severe in compound heterozygotes 35delG/L90P and 35delG/N206S than in 35delG homozygotes. Moderate or mild hearing impairment was more frequent in patients with 1 or 2 noninactivating mutations than in patients with 2 inactivating mutations. Of 93 patients, hearing loss was stable in 73, progressive in 21, and fluctuant in 2. Progressive hearing loss was more frequent in patients with 1 or 2 noninactivating mutations than in those with 2 inactivating mutations. In 49 families, hearing loss was compared between siblings with similar genotypes, and variability in terms of severity was found in 18 families (37%)., Conclusion: Genotype may affect deafness severity, but environmental and other genetic factors may also modulate the severity and evolution of GJB2-GJB6 deafness.

Sensorineural hearing defect and goiter are common features of Pendred's syndrome. The clinical diagnosis of Pendred's syndrome remains difficult because of the lack of sensitivity and specificity of the thyroid signs. The identification of PDS as the causative gene allowed molecular screening and enabled a re-evaluation of the syndrome to identify potential diagnostic characteristics. This report presents the clinical and genotypic findings of 30 French families, for whom a diagnosis of Pendred's syndrome had been made. Twenty-seven families had at least one mutated allele. Twenty-eight different mutations were identified, 11 of which had never been previously reported. The main clinical characteristics were: early hearing loss, fluctuation in terms of during deafness evolution, and the presence of an enlarged vestibular aqueduct.

Recent investigations identified a large deletion of the GJB6 gene in trans to a mutation of GJB2 in deaf patients. We looked for GJB2 mutations and GJB6 deletions in 255 French patients presenting with a phenotype compatible with DFNB1. 32% of the patients had biallelic GJB2 mutations and 6% were a heterozygous for a GJB2 mutation and a GJB6 deletion. Biallelic GJB2 mutations and combined GJB2/GJB6 anomalies were more frequent in profoundly deaf children. Based on these results, we are now assessing GJB6 deletion status in cases of prelingual hearing loss., (Copyright 2004 Wiley-Liss, Inc.)

Mutations in GJB2 are the most common cause of congenital nonsyndromic hearing loss. The controversial allele variant M34T has been hypothesized to cause autosomal dominant or recessive nonsyndromic hearing impairment and some in vitro data has been consistent with this hypothesis. In this report, we present the clinical and genotypic study of 11 families (seven familial forms of nonsyndromic sensorineural hearing loss (NSSNHL) and four sporadic cases) in which the M34T GJB2 variant has been identified. The M34T mutation did not segregate with the deafness in six of the seven familial forms of NSSNH. Eight persons with normal audiogram presented a heterozygous M34T variation and five normal hearing individuals were composite heterozygous for M34T and another GJB2 mutation. Four normal hearing individuals with a documented audiogram were M34T/35delG and one was M34T/(GJB6-D13S1830)del. Screening a French control population of 116 subjects we have found an M34T allele frequency of 1.72%. This percentage was not significatively different from the prevalence of the M34T allele in the deaf population, which was 2.12%. All these data suggest that the M34T variant is not clinically significant in human and is a frequent polymorphism in France.

Purpose: N,N-diethyl-2-[4-(phenylmethyl)phenoxy]ethanamine (DPPE; tesmilifene) is a novel agent that augments chemotherapy cytotoxicity in vitro and in vivo. A phase II trial combining DPPE and doxorubicin (DOX) in metastatic breast carcinoma showed increased response over that expected with DOX. We report a phase III trial comparing DOX with DPPE plus DOX in metastatic or recurrent breast cancer., Patients and Methods: Anthracycline-naive women with measurable metastatic disease were randomly assigned to receive, every 21 days, either DOX 60 mg/m(2) intravenously or DOX during the last 20 minutes of an 80-minute infusion of DPPE (5.3 mg/kg), in both cases to cumulative DOX doses of 450 mg/m(2). Patients receiving DPPE were aggressively premedicated to ameliorate toxicity. End points included progression-free survival (PFS), response rate (RR), and response duration (RD), quality of life (QOL), toxicity, and overall survival (OS)., Results: A planned interim analysis failed to detect an RR difference more than 5%. The study was closed to additional accrual and all DPPE was discontinued. The final analysis was conducted as planned after 256 progression events (median follow-up, 20.5 months). There was no significant difference in RR, RD, or PFS between arms. DPPE plus DOX was statistically superior to DOX in OS (hazard ratio, 0.66; 95% CI, 0.48 to 0.91; P =.021). DPPE plus DOX was associated with more gastrointestinal and CNS toxicity. No consistent influence on QOL was detected., Conclusion: This study demonstrated no advantage in RR, RD, or PFS but significantly superior OS for DPPE plus DOX. Additional studies of DPPE are warranted.

Mutations in GJB2, the gene encoding connexin-26 at the DFNB1 locus on 13q12, are found in as many as 50% of subjects with autosomal recessive, nonsyndromic prelingual hearing impairment. However, genetic diagnosis is complicated by the fact that 10%-50% of affected subjects with GJB2 mutations carry only one mutant allele. Recently, a deletion truncating the GJB6 gene (encoding connexin-30), near GJB2 on 13q12, was shown to be the accompanying mutation in approximately 50% of these deaf GJB2 heterozygotes in a cohort of Spanish patients, thus becoming second only to 35delG at GJB2 as the most frequent mutation causing prelingual hearing impairment in Spain. Here, we present data from a multicenter study in nine countries that shows that the deletion is present in most of the screened populations, with higher frequencies in France, Spain, and Israel, where the percentages of unexplained GJB2 heterozygotes fell to 16.0%-20.9% after screening for the del(GJB6-D13S1830) mutation. Our results also suggest that additional mutations remain to be identified, either in DFNB1 or in other unlinked genes involved in epistatic interactions with GJB2. Analysis of haplotypes associated with the deletion revealed a founder effect in Ashkenazi Jews and also suggested a common founder for countries in Western Europe. These results have important implications for the diagnosis and counseling of families with DFNB1 deafness.

Objective: To evaluate the symptoms leading to diagnosis and the quality of rehabilitation after cochlear implantation in Usher syndrome., Study Design: Retrospective cohort study., Setting: ENT department of a tertiary referral hospital., Patients: Among 210 patients given an implantation in the Ear, Nose, and Throat department, 185 were congenitally deaf and 13 had Usher syndrome (7.0%). Five had a family history of Usher, and eight were sporadic cases. Eleven cases were Usher type I, one was Usher type III, and one was not classified. The age at implantation ranged from 18 months to 44 years (mean, 6 years 1 month). The mean follow-up was 52 months (range, 9 months to 9 years)., Main Outcome Measures: All patients had audiophonological and clinical examination, computed tomography scan of the temporal bones, ophthalmologic examination with fundoscopy, and an electroretinogram. Cerebral magnetic resonance imaging and vestibular examination were performed in 9 of 13 and 10 of 13 cases, respectively. Logopedic outcome measured preimplant and postimplant closed- and open-set word recognition and oral expression at follow-up., Results: The most frequent initial sign of Usher syndrome was delayed walking, with a mean age of 20 months. Among the 172 other congenitally deaf children with implants, when deafness was not associated with other neurologic disorders, the mean age at walking was 14 months (p < 0.001). The fundoscopy was always abnormal after the age of 5 years, and the electroretinogram was abnormal in all cases. Vestibular function was abnormal in all but one case (nonclassified). The computed tomography scan and the magnetic resonance imaging were always normal. Logopedic results with cochlear implants showed good perception skills in all but one case. The best perceptive results were obtained in children implanted before the age of 9 years. Oral language had significantly progressed in 9 of 13 at follow-up. There was no relation between the visual acuity and the logopedic results., Conclusion: The earliest clinical sign associated with deafness evoking Usher syndrome is late walking. The electroretinogram is the only reliable examination to enable the diagnosis. When severe profound deafness is associated with late walking, the electroretinogram should be systematically proposed. Logopedic results are linked to precocity of implantation, and early Usher's diagnosis contributes to optimize speech therapy.

Hearing impairment is the most frequent sensory defect in children, with a genetic basis in about 50% of cases. Several point mutations and deletions in mitochondrial DNA (mtDNA) have been identified in non-syndromic sensorineural hearing loss (NSSNHL). Beside the frequent A1555G mutation, a number of mutations in tRNAs have been reported recently, but their incidence remains unknown. We identified the T7511C mutation in the tRNASer(UCN) gene in two French families with isolated deafness. Maternal transmission was obvious in both. The 15 patients with hearing impairment exhibited a variable disease phenotype in terms of onset, severity, and progression. T7511C was present in all the patients screened. Homoplasmic and heteroplasmic levels were observed and did not correlate with the severity of the disease. T7511C was also present in 12 hearing offspring of the oldest deaf mothers, confirming the existence of modulatory factors. Our data suggest that this mtDNA mutation should be screened for in all cases of familial NSSNHL compatible with maternal transmission.

Objective: To evaluate difficulties encountered in genetic counseling in deaf children carrying connexin 26 gene (CX26 or GJB2) mutations., Design: Prospective study., Setting: Outpatients, tertiary referral center., Patients: Ninety-six unrelated deaf children in whom CX26 mutations had been detected consecutively. Children were recruited to a center for genetic counseling for deaf children, and all had congenital deafness, sporadic or familial., Results: In 63 children, deafness was clearly a DFNB1 form with autosomal recessive inheritance: 47 of the 63 were homozygous for the most frequent mutation, the deletion of G at position 35 (35delG); 16 of 63 carried on both alleles of CX26 frameshift or stop mutations, or missense mutations affecting a critical region of the gene. In 33 of 96 children, genetic counseling was difficult: 21 of 33 had a single mutation detected, 11 of 33 had new missense mutations or mutations whose pathogenicity remains debated in the literature, and 1 of 33 had a genotype with both a recessive mutation (35delG) and a mutation acting as a dominant mutation., Conclusions: Interpretation of results for the molecular diagnosis of mutations in the connexin 26 gene is difficult in almost one third of cases. Close collaboration between geneticists familiar with deafness and otolaryngologists is essential to provide a high standard of genetic advice.