Clinical and genetic findings of two cases with Apert syndrome / Hallazgos clínicos y genéticos de dos casos con síndrome de Apert

Abstract Background: Craniosynostosis is described as the premature fusion of cranial sutures that belongs to a group of alterations which produce an abnormal phenotype. Case report: Two unrelated female patients with clinical findings of Apert syndrome-characterized by acrocephaly, prominent frontal region, flat occiput, ocular proptosis, hypertelorism, down-slanted palpebral fissures, midfacial hypoplasia, high-arched or cleft palate, short neck, cardiac anomalies and symmetrical syndactyly of the hands and feet-are present. In both patients, a heterozygous missense mutation (c.755C>G, p.Ser252Trp) in the FGFR2 gene was identified. Conclusions: Two cases of Apert syndrome are described. It is important to recognize this uncommon entity through clinical findings, highlight interdisciplinary medical evaluation, and provide timely genetic counseling for the family.

Resumen Introducción: Las craneosinostosis se describen como la fusión prematura de las suturas craneales y resultan un grupo de alteraciones que producen un fenotipo anormal. Caso clínico: En este informe de casos se presentan dos pacientes de sexo femenino no emparentadas con hallazgos clínicos del síndrome de Apert, caracterizado por acrocefalia, región frontal prominente, occipucio plano, proptosis ocular, hipertelorismo, fisuras palpebrales hacia abajo, hipoplasia mediofacial, paladar alto o hendido, cuello corto, cardiopatía congénita y sindactilia simétrica en manos y pies. En ambas pacientes se identificó una mutación cambio de sentido en heterocigosis (c.755C>G, p.Ser252Trp) en el gen FGFR2. Conclusiones: Se presentan dos casos de síndrome de Apert. Es importante reconocer a través de los hallazgos clínicos esta entidad infrecuente, resaltar la evaluación médica interdisciplinaria y proporcionar un oportuno asesoramiento genético a la familia.

Clinical and genetic findings of two cases with Apert syndrome.

Background: Craniosynostosis is described as the premature fusion of cranial sutures that belongs to a group of alterations which produce an abnormal phenotype. Case report: Two unrelated female patients with clinical findings of Apert syndrome-characterized by acrocephaly, prominent frontal region, flat occiput, ocular proptosis, hypertelorism, down-slanted palpebral fissures, midfacial hypoplasia, high-arched or cleft palate, short neck, cardiac anomalies and symmetrical syndactyly of the hands and feet-are present. In both patients, a heterozygous missense mutation (c.755C>G, p.Ser252Trp) in the FGFR2 gene was identified. Conclusions: Two cases of Apert syndrome are described. It is important to recognize this uncommon entity through clinical findings, highlight interdisciplinary medical evaluation, and provide timely genetic counseling for the family.

Introducción: Las craneosinostosis se describen como la fusión prematura de las suturas craneales y resultan un grupo de alteraciones que producen un fenotipo anormal. Caso clínico: En este informe de casos se presentan dos pacientes de sexo femenino no emparentadas con hallazgos clínicos del síndrome de Apert, caracterizado por acrocefalia, región frontal prominente, occipucio plano, proptosis ocular, hipertelorismo, fisuras palpebrales hacia abajo, hipoplasia mediofacial, paladar alto o hendido, cuello corto, cardiopatía congénita y sindactilia simétrica en manos y pies. En ambas pacientes se identificó una mutación cambio de sentido en heterocigosis (c.755C>G, p.Ser252Trp) en el gen FGFR2. Conclusiones: Se presentan dos casos de síndrome de Apert. Es importante reconocer a través de los hallazgos clínicos esta entidad infrecuente, resaltar la evaluación médica interdisciplinaria y proporcionar un oportuno asesoramiento genético a la familia.

Normal sweat chloride test does not rule out cystic fibrosis.

Basaran AE, Karatas-Torun N, Maslak IC, Bingöl A, Alper ÖM. Normal sweat chloride test does not rule out cystic fibrosis. Turk J Pediatr 2017; 59: 68-70. A 5-month-old patient presented with complaints of fever and cough. He was hospitalized with the diagnosis of bronchopneumonia and pseudo-Bartter's syndrome. Patient was further investigated for diagnosis of cystic fibrosis. The chloride (Cl) level in sweat was determined within the normal range (25.1 mmol/L, 20.3 mmol/L). CFTR (Cystic Fibrosis Transmembrane Regulator gene; NM_000492.2) genotyping results were positive for p.E92K; p.F1052V mutations. The patient was diagnosed with cystic fibrosis. In our patient, with features of CF and normal sweat test, mutation analysis was helpful for the diagnosis of cystic fibrosis.

Perinatal Diagnostic Approach to Fetal Skeletal Dysplasias: Six Years Experience of a Tertiary Center.

Skeletal dysplasias (SDs) constitute a group of heterogeneous disorders affecting growth morphology of the chondro-osseous tissues. Prenatal diagnosis of SD is a considerable clinical challenge due to phenotypic variability. We performed a retrospective analysis of the fetal autopsies series conducted between January 2006 and December 2012 at our center. SD was detected in 54 (10%) out of 542 fetal autopsy cases which included; 11.1% thanatophoric dysplasia (n = 6), 7.4% achondroplasia (n = 4), 3.7% osteogenesis imperfect (n = 2), 1.9% Jarcho-Levin Syndrome (n = 1), 1.9% arthrogryposis (n = 1), 1.9% Dyggve-Melchior-Clausen syndrome (n = 1), 72.1% of dysostosis cases (n = 39). All SD cases were diagnosed by ultrasonography. In 20 of the cases, amniocentesis was performed, 4 cases underwent molecular genetic analyses. Antenatal identification of dysplasia is important in the management of pregnancy and in genetic counseling. Our data analysis showed that SD is usually detected clinically after the 20th gestational week. Genetic analyses for SD may provide early diagnosis and management.

Clinicogenetic study of Turkish patients with syndromic craniosynostosis and literature review.

BACKGROUND: Fibroblast growth factor receptor 2 mutations have been associated with the craniosynostotic conditions of Apert, Crouzon, Pfeiffer, Saethre-Chotzen, Jackson-Weiss, Beare-Stevenson cutis gyrata, and Antley-Bixler syndromes in various ethnic groups. METHODS: Thirty-three unrelated Turkish patients (12 with Apert syndrome, 14 with Crouzon syndrome, six with Pfeiffer syndrome, and one with Saethre-Chotzen syndrome) and 67 nonsyndromic craniosynostosis patients were screened for mutations in exons IIIa and IIIc of the FGFR2 gene by denaturing high-performance liquid chromatography and confirmed by direct sequencing. RESULTS: We detected several pathogenic mutations in 11/33 (33%) patients with Apert syndrome (four with p.Pro253Arg; seven with p.Ser252Trp) and 8/33 (24%) patients with Crouzon syndrome (three with p.Trp290Arg, one with p.Cys342Tyr, p.Cys278Phe, p.Gln289Pro, and a novel p.Tyr340Asn mutation) and five (15%) with Pfeiffer syndrome (p.Cys342Arg, p.Pro253Arg, p.Trp290Arg, and p.Ser351Cys). No FGFR2 gene mutation was detected in any of the patients with Saethre-Chotzen syndrome and nonsyndromic craniosynostosis. CONCLUSIONS: Our results indicate that the majority of Turkish patients with syndromic craniosynostosis have detectable genetic changes with an overall frequency of 72.7%. Because this is the first molecular genetic report from a Turkish cohort, the identified spectrum profile of FGFR2 mutations of the syndromic craniosynostotic patients would be very helpful for understanding the genotype-phenotype relationship and has a great value for diagnosis, prognosis, and genetic counseling.

Analysis of TPO gene in Turkish children with iodide organification defect: identification of a novel mutation.

The objective was to determine molecular genetic analysis of the TPO gene in Turkish children with iodide organification defect (IOD). Patients with a diagnosis of primary hypothyroidism were evaluated. Subjects having a definite diagnosis of autoimmune thyroiditis, thyroid gland dysplasia and, or iodine deficiency were excluded. A total of 10 patients from nine unrelated Turkish families, with an unknown etiology of hypothyroidism, and with a presumptive diagnosis of IOD were included in the study. A perchlorate discharge test (PDT) was performed to all subjects, and sequence analysis of TPO gene was applied in patients with a positive PDT. Five out of 10 patients have a total IOD, while the five remaining patients have a partial IOD according to PDT results. In two sisters, one has a partial and the other one has a total IOD a novel homozygous nonsense p.Q315X mutation was found in exon 8. Additionally, a previously known homozygous missense p.R314W mutation was detected in the same exon in another patient with a total IOD. No TPO gene mutation was detected in any of the seven remaining patients. Two different TPO gene mutations were found to be responsible for IOD in two unrelated Turkish families from the same ethnic background. More subjects should be screened for detecting the prevalence and spectrum profile of TPO mutations in our population that might be helpful for understanding the pathophysiology of congenital hypothyroidism.

Mutational spectrum of MYO15A: the large N-terminal extension of myosin XVA is required for hearing.

Human MYO15A is located on chromosome 17p11.2, has 66 exons and encodes unconventional myosin XVA. Recessive mutations of MYO15A are associated with profound, nonsyndromic hearing loss DFNB3 in humans, and deafness and circling behavior in shaker 2 mice. In the inner ear, this motor protein is necessary for the development of hair cell stereocilia, which are actin-filled projections on the apical surface and the site of mechanotransduction of sound. The longest isoform of myosin XVA has 3,530 amino acid residues. Two isoform classes of MYO15A are distinguished by the presence or absence of 1,203 residues preceding the motor domain encoded by alternatively-spliced exon 2. It is not known whether this large N-terminal extension of myosin XVA is functionally necessary for hearing. We ascertained approximately 600 consanguineous families segregating hereditary hearing loss as a recessive trait and found evidence of linkage of markers at the DFNB3 locus to hearing loss in 38 of these families ascertained in Pakistan (n=30), India (n=6), and Turkey (n=2). In this study, we describe 16 novel recessive mutations of MYO15A associated with severe to profound hearing loss segregating in 20 of these DFNB3-linked families. Importantly, two homozygous mutant alleles-c.3313G>T (p.E1105X) and c.3334delG (p.G1112fsX1124) of MYO15A-located in exon 2 are associated with severe to profound hearing loss segregating in two families. These data demonstrate that isoform 1, containing the large N-terminal extension, is also necessary for normal hearing.

Mutation spectrum of the CFTR gene in Taiwanese patients with congenital bilateral absence of the vas deferens.

BACKGROUND: Clinically affected cystic fibrosis (CF) patients present a spectrum of genital phenotypes ranging from normal fertility to moderately impaired spermatogenesis and congenital bilateral absence of vas deferens (CBAVD). Little is known about the CF incidence in the Taiwanese population. It has been shown that the CBAVD in men without clinical evidence of CF is associated with a high incidence of mutated CFTR (cystic fibrosis transmembrane conductance regulator) alleles. In order to understand the involvement of the CFTR gene in the aetiology of Asian/Taiwanese male infertility, we screened the entirety of the CFTR gene in 36 infertile males with CBAVD. METHODS: Temporal temperature gradient gel electrophoresis (TTGE) followed by direct DNA sequencing was used. RESULTS: Five mutations, p.V201M, p.N287K, c.-8G > C (125G > C), p.M469I and p.S895N, were found in five of the patients. p.N287K occurred in the first transmembrane-spanning domain, p.M469I in the first ATP-binding domain and p.S895N in the second transmembrane-spanning domain, were novel. In addition, seven homozygous and seven heterozygous 5T alleles in the intron 8 poly(T) tract were found. The overall frequency of CFTR mutant alleles in Taiwanese CBAVD males was 26 out of 72 = 36%. This finding was lower than the published frequency of CFTR mutations in other ethnic CBAVD patients (ranging from 50 to 74%). The frequency of p.M470V in Taiwanese CBAVD patients is not significantly different from that in the general population (P = 0.12). CONCLUSIONS: The results of this study add to the short list of Taiwanese/Asian CFTR mutations. Unlike Caucasian patients, the CFTR mutations cannot account for the majority of Taiwanese CBAVD. This is consistent with the low incidence of CF in the Asian/Taiwanese population. Furthermore, the mutation spectrum of CFTR in CBAVD patients does not overlap with the Caucasian CFTR mutation spectrum.

The necessity of complete CFTR mutational analysis of an infertile couple before in vitro fertilization.

OBJECTIVE: To determine the genotype of a triplet resulted from an IVF procedure, with discordant cystic fibrosis (CF) phenotype. DESIGN: Molecular diagnosis of CF. SETTING: Affected triplet followed at the CF Clinic Center of Children's Hospital Los Angeles was referred to Molecular Genetics Laboratory at Georgetown University Medical Center for comprehensive DNA analysis of the cystic fibrosis transmembrane regulator (CFTR) gene. PATIENT(S): Three affected children and the healthy parents with negative family history of CF. MAIN OUTCOME MEASURE(S): Temporal temperature gradient gel electrophoresis and direct DNA sequencing were used to detect and to identify the mutations. RESULT(S): The child with classic CF had DeltaF508 and R553X mutations. Two children with mild CF symptoms had DeltaF508 and R117C. The father carried two mutations, R553X and R117C. The mother is a carrier for DeltaF508. CONCLUSION(S): Mutational analysis of the CFTR gene should always be recommended to the infertile couples seeking for IVF. The CFTR mutation screening would be essential if the man has congenital bilateral absence of vas deferens (CBAVD) despite the negative family history of CF. Option of complete CFTR gene analysis at a cost of about 1,500-2,000 dollars should be made available if one mutation is found in the male partner with congenital bilateral absence of vas deferens.

Identification of novel and rare mutations in California Hispanic and African American cystic fibrosis patients.

In ethnic heterogeneous California, complete genetic information is currently lacking to build solid population-based cystic fibrosis (CF) screening programs because a large proportion of mutations in the cystic fibrosis transmembrane conductance regulator gene (CFTR/ABCC7) are still unknown, especially in non-Caucasian patients. A total of 402 [46 African American+356 Hispanic] Hispanic and African American patients from California CF patient registry were included in this study. Patients with at least one unidentified mutant allele were asked to donate blood samples for further analysis, first by Genzyme Genetics for a panel of 87 known mutations, followed by temporal temperature gradient gel electrophoresis (TTGE) scanning of the entire coding exons of CFTR gene. A total of eight novel mutations; one missense mutation, one splice-site mutation and six frame-shift mutations were identified. In addition to the eight novel mutations, 20 [corrected] distinct rare mutations that are not in the current available commercial mutation panels were identified by TTGE. The overall detection rate was raised to 95.7% for African American and 94.5% for Hispanic. The discovery of recurrent rare and novel mutations improves the diagnosis and care of persons with CF and improves our ability to adequately and equitably provide screening and genetic counseling services to non-Caucasians.

Detection of CFTR mutations using temporal temperature gradient gel electrophoresis.

Cystic fibrosis (CF), caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, is one of the most common autosomal recessive diseases with variable incidences and mutation spectra among different ethnic groups. Current commercially available mutation panels designed for the analysis of known recurrent mutations have a detection rate between 38 to 95%, depending upon the ethnic background of the patient. We describe the application of a novel mutation detection method, temporal temperature gradient gel electrophoresis (TTGE), to the study of the molecular genetics of Hispanic CF patients. TTGE effectively identified numerous rare and novel mutations and polymorphisms. One interesting observation is that the majority of the novel mutations are splice site, frame shift, or nonsense mutations that cause severe clinical phenotypes. Our data demonstrate that screening of the 27 exons and intron/exon junctions of the CFTR gene by TTGE greatly improves the molecular diagnosis of Hispanic CF patients.

Simultaneous suppression of epidermal growth factor receptor and c-erbB-2 reverses aneuploidy and malignant phenotype of a human ovarian carcinoma cell line.

Coexpression of epidermal growth factor receptor (EGFR) and c-erbB-2 in 47-68% of ovarian cancer cells indicate their strong association with tumor formation. We examined the effects of simultaneous antisense- or immunosuppression of EGFR and c-erbB-2 expression on the invasive phenotype, aneuploidy, and genotype of cultured human ovarian carcinoma cells (NIH:OVCAR-8). We report here that suppression of both EGFR and c-erbB-2 results in regression of aneuploidy and genomic imbalances in NIH:OVCAR-8 cells, restores a more normal phenotype, and results in a more normal gene expression profile. Combined with cytogenetic analysis, our data demonstrate that the regression of aneuploidy is due to the selective apoptosis of double antisense transfected cells with highly abnormal karyotype.

Detection of novel CFTR mutations in Taiwanese cystic fibrosis patients.

BACKGROUND AND PURPOSE: Cystic fibrosis (CF) in Asian populations is very rare. We performed molecular genetic analysis in 2 Taiwanese CF patients for detection of cystic fibrosis transmembrane conductance regulator (CFTR) mutations. METHODS: Temporal temperature gradient gel electrophoresis (TTGE) was used for mutation detection, and direct sequencing was used for identification of mutations. RESULTS: In one patient, 2 novel mutations, E7X and 989-992insA, were identified and the carrier status of his parents was confirmed. In the other patient, 3 mutations, S895N, 2215insG, and 1898+5G>T, were found. The 2215insG and S895N were found cis in the same chromosome. These splice site, frameshift, and nonsense mutations produce severely truncated CFTR polypeptides which lack a transmembrane domain, nucleotide binding folds, and the regulatory region, and are predicted to be null in CFTR function. CONCLUSIONS: These cases underscore the importance of comprehensive mutation analysis of Taiwanese CF patients. Definitive molecular findings can confirm the clinical diagnosis and facilitate patient management, carrier testing, and genetic counseling. Furthermore, there is an urgent need to understand the mutation spectrum and the clinical features of the CFTR gene in Asian patients in order that a mutation panel can be established for effective screening of CF chromosomes.