ASN540SER mutation is associated with a mild form of hypochondroplasia: a 7 years follow-up in an Italian boy.

Skeletal dysplasias (SKD) are genetic disorders that result in the abnormal development of part or all of the skeleton and are commonly associated with short stature. The most common SKDs that typically result in short stature include achondroplasia/hypochondroplasia (HCH) both caused by different mutations in the same gene. HCH diagnosis is based on the clinical appearance during development and conventional X-ray findings. In about 70% of patients, missense mutations in the gene coding for the fibroblast Growth Factor Receptor 3 (FGFR3) affects the amino acid at position 540, mostly resulting in the amino acid exchange N540K.Subjects with HCH, heterozygous for the N540K substitution are significantly more disproportionate than individuals without this mutation. We report the clinical and radiographic features of an Italian family with HCH with an unusual N540S mutation, inside the common mutation hot spot of this condition. This is the first case reported in Italy and the third in the literature. During a 7-years-follow-up, the boy started the puberty at the age of 11.3 years and the growth spurt was observed between 13.7 and 14.9 years (+ 9.1 cm.).During pubertal development the sitting height (SDS) improved from - 1.5 to - 0.6 and the subischial leg length (SDS) progressed from - 2.6 to - 3.3.At the age of 16.7 year the standing height was 157.6 cm ( - 2.4 SDS), testicular volume was 15 ml and bone age 16.5 year. The present study and the other two cases reported in the literature stress the important role of the asn 540 site in the tyrosine kinase I domain in the pathogenesis of HCH and underline the importance that, in patients with HCH who do not have the common N540K mutation, sequence analysis of the tyrosine kinase I domain of FGFR3 should be performed to exclude other changes in that region.

Familial pericentric inversion of chromosome 18: intrafamilial variability of the recombinant dup(18q).

A pericentric inversion of chromosome 18 [inv(18)(p11.32q22)] and its recombinants has been studied in a three-generation family. A mother/son couple, carrying the rec dup(18q), showed dysmorphisms and short stature but only the son had mild mental retardation and speech delay. Karyotype, FISH analysis with subtelomeric probes and a 0.8 Mb array-CGH investigations were used to analyze this recombinant, demonstrating no genomic differences between the two relatives. This is the first observation of familial transmission of a rec dup(18q), showing that this recombinant is associated with a mild phenotype with variable clinical picture.

Identification of 13 novel NLRP7 mutations in 20 families with recurrent hydatidiform mole; missense mutations cluster in the leucine-rich region.

BACKGROUND: NLRP7 (NALP7) has recently been identified as the causative gene for familial recurrent hydatidiform mole (FRHM), a rare autosomal recessive condition in which affected women have recurrent molar pregnancies of diploid biparental origin. To date only a small number of affected families have been described. Our objectives were to investigate the diversity of mutations and their localisation to one or both isoforms of NLRP7, by screening a large series of women with FRHM and to examine the normal expression of NLRP7 in ovarian tissue. METHODS: Fluorescent microsatellite genotyping of molar tissue was used to establish a diagnosis of FRHM. Twenty families were subsequently screened for mutations in NLRP7 using DNA sequencing. Expression of NLRP7 in the ovary was examined by immunohistochemical staining. RESULTS: 16 different mutations were identified in the study, 13 of which were novel. Missense mutations were found to be present in transcript variant 2 of NLRP7 and cluster in the leucine-rich region (LRR). A man with two affected sisters and homozygous for the p.R693P mutation had normal reproductive outcomes. In the normal human ovary, NLRP7 expression is confined to the oocytes and present at all stages from primordial to tertiary follicles. CONCLUSION: 13 novel mutations in NLRP7 were identified. We confirm that mutations in NLRP7 affect female but not male reproduction, and provide evidence that transcript variant 2 of NLRP7 is the important isoform in this condition. The mutation clustering seen confirms that the LRR is critical for normal functioning of NLRP7.

An intermediate phenotype between Hay-Wells and Rapp-Hodgkin syndromes in a patient with a novel P63 mutation: confirmation of a variable phenotypic spectrum with a common aetiology.

The ankyloblepharon-ectodermal defects-cleft lip and palate (Hay-Wells or AEC) and the Rapp-Hodgkin syndrome (RHS) are rare autosomal dominant ectodermal dysplasias due to mutations in the transcription factor gene P63. Both are caused by mutations affecting SAM or TID domains of TP63 protein. The two disorders share common features and may represent different phenotypic expressions of the same clinical entity. To date more than 20 P63 mutations have been described associated with AEC and RHS, the majority of which are missense or nonsense mutations. Molecular heterogeneity cannot account for the clinical heterogeneity, because the same mutations were observed both in patient with RHS and with AEC syndrome. Here we report on a novel P63 mutation (the first repeat variation described in the gene) in a patient showing overlapping phenotype of AEC and RH syndromes.

Prenatal diagnosis of a de novo satellited chromosome 18 (18ps) associated with 18p deletion.

De novo satellited non-acrocentric chromosomes are very rare findings in prenatal diagnosis. Here we report the first case of a de novo 18ps, associated with del(18p), detected at prenatal diagnosis. A 37 years old woman underwent Chorionic Villus Sampling (CVS) for advanced maternal age. Cytogenetic analysis on direct CVS preparation (CVSc) revealed a male karyotype with a nonfamilial satellited 18ps and a reciprocal translocation t(17;19)(P11.1;q11) of maternal origin. The mesenchimal CVS culture (CVSm) showed a mosaic of cell lines with various involvement of chromosome 18: 18ps [36/70]/ r(18) [25/70]/ del(18p) [3/70]/ -18 [6/70]. Amniotic fluid cells (AFC) confirmed the homogeneous karyotype found at CVSc. The molecular cytogenetic characterization, performed on AFC, allowed the following diagnosis: 46,XY, +15, dic(15;18)(p11.1;p11.2), t(17;19)(p11.1;q11)mat. ish dic(15;18)(tel 18p-, D15Z1+, wcp18-, wcp 18+, D18Z1+, tel 18q+). The foetal autopsy disclosed subtle facial dysmorphisms and corpus callosum hypoplasia. In case of prenatal detection of de novo terminal ectopic NORs an accurate cytogenetic and molecular analysis should be performed in order to rule out subtle unbalancements.

Paracentric inversion of Yq and review of the literature.

We report on the second prenatal diagnosis of familial paracentric inversion of the long arm of Y chromosome [46, X, inv(Y)(q11.2q12)]. The anomaly was detected through an amniocentesis performed because of advanced maternal age. The inversion has been detected by standard GTG banding methods and better characterized by FISH with painting probe and specific satellite probes DYZ1 and DYZ3. The inversion derived from phenotypically normal father. Pregnancy was uneventful and an healthy child was born. We discuss the issue concerning genetic prenatal counselling of this rare condition and we report the clinical follow up of the child.

FGFR3 mutation in thanatophoric dysplasia type 1 with bilateral cystic renal dysplasia: coincidence or a new association?

Thanatophoric dysplasia (TD) is a lethal dwarfism condition due to missense mutations in the fibroblast growth factor receptor 3 (FGFR3) gene. Examination of TD patients reveals mainly the involvement of the skeletal system and the brain, but also renal and cardiovascular anomalies have been described. We report the prenatal detection of TD type 1 (TD1) associated with bilateral cystic renal dysplasia (CRD) Potter's type II, in which the molecular analysis reveals the typical Arg248Cys substitution in the FGFR3 gene. CRD has not been previously described in TD or other conditions due to FGFR3 mutations, but occurs in Apert syndrome (due to FGFR2 mutations). The possible involvement of renal developmental defect in FGFR3 mutations is discussed.

Nonhomologous Robertsonian translocations (NHRTs) and uniparental disomy (UPD) risk: an Italian multicentric prenatal survey.

OBJECTIVES: The risk of uniparental disomy (UPD) occurrence associated with the prenatal finding of balanced nonhomologous Robertsonian translocations (NHRTs) has been estimated only on limited empirical data. The aim of the study was to verify the estimate of the general risk, to get narrower confidence intervals by cumulating the data and to obtain risk estimates for specific translocation types. METHODS: We tested for UPD 160 prenatal specimens referred to the participant centers after the cytogenetic finding of NHRT. RESULTS: One case of upd(14)mat was found, associated with a 45,XX,der(14;22)mat fetal karyotype. The general empirical risk of UPD occurrence in NHRT carrier fetuses, corrected for the actual number of chromosomes analyzed, was 0.76% (95% CI 0.02-4.25%). Cumulative data with previous studies gives a general risk of UPD associated with NHRT of 0.80% (95% CI 0.17-2.34%). The UPD risk for the specific NHRT der(13;14) did not significantly differ from that of the other NHRTs taken together. CONCLUSION: The present survey confirms the previously estimated risk of occurrence of UPD in offspring of NHRT carriers as a low, but not negligible risk, worth being investigated in prenatal diagnosis.

Exploring the clinical and epidemiological complexity of GJB2-linked deafness.

GJB2 mutation analysis was performed in 179 unrelated subjects with sporadic or familial hearing loss (HL). Among 57 families, 18 showed a vertical transmission of HL, the disease being present in two or three generations. Besides 155 nonsyndromic cases, 24 patients presenting with extra-auditory clinical signs were included in the molecular study. GJB2 mutation analysis was also performed in 19 subjects with an anamnestic history of perinatal risks factors for acquired HL. The 35delG mutation accounted for 22.1% of analyzed chromosomes in sporadic cases and 39.4% in familial cases; 35delG prevalence reached 41% in autosomal recessive and 44.4% in pseudodominant pedigrees. Two novel GJB2 mutations were identified in compound heterozygosity with 35delG allele (D159V, 284ins/dup[CACGT]). Two 35delG homozygous subjects were identified among HL cases classified as environmental in origin. Four patients 35delG heterozygous (35delG/V95M, 35delG/L90P, 35delG/167delT, and 35delG/?) and two homozygous presented with extra-auditory clinical signs involving different organs (skin, vascular system, hemopoietic lineages, and thyroid). In a high proportion of 35delG heterozygous HL patients (52%), no second GJB2 mutation was detected. The reported data highlight the complexity of the genetic epidemiology of GJB2-linked deafness, further enlarging the spectrum of situations in which GJB2 mutation analysis should be performed. The presence of extra-auditory signs in a significant portion of GJB2-mutated patients suggests the possibility that GJB2 loss of function could contribute to clinical phenotypes presenting in association with deafness. This hypothesis deserves further investigation. The failure to identify a presumed partnering GJB2 mutation in a high proportion of deaf patients remains a challenging problem to be clarified.

Mole maker phenotype: possible narrowing of the candidate region.

Recent data has suggested that familial recurrent hydatidiform mole is a rare autosomal recessive trait in women experiencing this gestational disease (MIM 231090). Here we provide molecular data on an additional family confirming that recurrent familial hydatidiform moles are diploid, biparental and arise from independent conceptions. A narrowing of the gene interval on chromosome 19q13.3-13.4 is suggested by haplotype analysis in two sisters.

Prenatal UPD testing survey in Robertsonian translocations.

A systematic search was made for uniparental disomy (UPD) in familial or de novo balanced Robertsonian translocations, identified by prenatal cytogenetic investigations. Parent-of-origin studies were performed using molecular markers for both chromosomes involved in the translocation. No UPD cases were identified out of 23 analysed cases. The results presented here, combined with other available data, provide preliminary elements for genetic counselling in these common chromosomal rearrangements.

Clinical and radiological evaluation in children with microtia.

The management of a child with congenital ear malformation, in particular if the external ear is severely involved, is difficult because of the complexity of the therapeutic problem, and that of parental anxiety. It is very important to plan a complete therapeutic/habilitative programme as soon as possible, even if surgical procedures are delayed. Diagnostic imaging plays an important role in the global assessment of a child with microtia, in order to diagnose possible associated external auditory canal, middle and inner ear malformations. For these reasons our diagnostic protocol for children with microtia includes otological and audiological evaluation, clinical genetics and radiological imaging, from the neonatal period. Here, data are reported on 27 children with microtia who completed the diagnostic protocol. In eight of 27 cases microtia was bilateral: in unilateral cases the right side was affected more frequently. Other congenital malformations were diagnosed in 41% of cases. A high correlation between the degree of microtia and the frequency of external and middle ear dysplasias was found, in accordance with larger studies of the literature. Inner ear malformations were found less frequently, but without apparent correlation with the degree of microtia. The fact that children with microtia may also have severe inner ear malformations is emphasized.

Molecular and biological features of two new human squamous and adenocarcinoma of the lung cell lines.

Two human cancer cell lines were established from metastatic lesions of an adenocarcinoma (RAL) and a squamous cell (CAEP) carcinoma of the lung. The clinical histories of the patients from whom the cell lines were derived are reported. The lines were maintained in continuous culture with doubling times of 65 (RAL) and 50 (CAEP) hours. The RAL and CAEP cell lines, whose morphology and ultrastructural features are presented, showed extensively rearranged karyotypes with modal number of 85 (RAL) and 98 (CAEP). In particular, chromosome 2 pentasomy and several clonal markers were evident in the RAL cells, whereas a telomeric deletion of chromosome 1, del (1)(q32), was observed in the CAEP cells. The morphologic data were confirmed by high expression of specific antigens for each histotype. A marked positivity of the neuron-specific enolase (NSE) levels was evident by immunoenzymatic assays in the cell lines cytosol with respect to those present in the respective patient's sera. No amplification or rearrangements were evident in the CMYC, LMYC, NMYC, INT-2, ERBB2, HRAS, KRAS, MOS, HST-1 genes by Southern blotting analysis in each cell line. Point mutations in exon 1 of KRAS and in exon 7 of TP53 were evident by polymerase chain reaction (PCR)-DNA sequencing in the RAL cell line, whereas no alterations were present in the HRAS and RB genes. The four genes studied did not show point mutations in the CAEP cell line. The RAL cell line was resistant to all the drugs tested, whereas the CAEP cells were sensitive to vinblastine. These cell lines may represent useful experimental models to investigate lung cancer biology and anticancer drug response.

Molecular genetics and in vitro sensitivity of a new human cell line, KKP, from a gastric adenocarcinoma.

A new cancer cell line (KKP) was established from an ascitic effusion of an advanced gastric adenocarcinoma, intestinal type. The line has been maintained in continuous monolayer culture with a doubling time of 48 hours for more than 2 years. KKP cells, whose ultrastructural features are presented, showed an aneuploid DNA content, a modal number of 53 chromosomes, and the presence of one double minute chromosome. The karyotype showed trisomies of chromosomes 7, 12, 13, and 14, tetrasomy of chromosome 18, a reciprocal translocation [t(1;20)(q21;p11.2)], and a [t(4;?)] rearrangement. No amplification or rearrangements were evident in the c-MYC, c-ERB B2, H-RAS, INT-2, HST-1, c-MOS, and K-RAS genes, whereas somatic rearrangements were present in the sequences corresponding to c-MET and cyclin E genes by Southern blotting analysis. Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis of P53 and RB genes did not reveal alterations or point mutations in the SSCP pattern of conformers. The chemosensitivity pattern assay of the KKP cell line indicated that it was sensitive to cisplatin, etoposide, and doxorubicin and resistant to 4'-hydroperoxycyclophosphamide. The clinical history of the patient from whom the cell line was derived is reported and compared with the results observed in the cell line in vitro. High levels of the tumor-associated antigens CEA (carcinoembryonic antigen) and CA19-9 were evident in the KKP cytosol, whereas the KKP spent culture medium maintained the same low levels of CEA and CA 19-9 found in the patient's serum. This new cell line may represent a useful tool for studying the biology of gastric cancer and for planning new therapeutic approaches.

Chromosomal alterations, biological features and in vitro chemosensitivity of SCLC-R1, a new cell line from human metastatic small cell lung carcinoma.

A new human cancer cell line was established from a metastatic lesion of a small cell lung carcinoma (SCLC-R1) and maintained in continuous culture with a doubling time of 62 h. The SCLC-R1 line, whose ultrastructural features are presented, showed a diploid DNA content, a translocation involving chromosome 16 [t(16;?)(q24;?)] and noticeable deletions in the FHIT (fragile histidine triad) region in the short arm of chromosome 3 [del(3)(p14)] and in the telomeric region of the short arm of chromosome 12 [del(12)(p13)]. The involvement of 12p in metastatic small cell lung cancer is reported here for the first time. No amplification or rearrangements were evident in the c-myc, L-myc, N-myc, int-2, c-erbB-2, H-ras, K-ras, c-mos, and hst-1 genes by Southern blot analysis. Wild-type p53, RB, K-ras and H-ras genes were evident by polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) analysis. The neuron specific enolase (NSE) level was much higher in the cell line's cytosol than in the patient's serum and the cell line also had high expression of chromogranin A and cytokeratin 19. SCLC-R1 cells were sensitive to cisplatin, carboplatin and doxorubicin. The clinical history of the patient from whom the cell line was derived is reported. The characteristics of this new cell line indicate it to be a useful experimental model to investigate lung cancer biology and anticancer drug response.

Chromosomal aberrations induced by BK virus T antigen in human fibroblasts.

Human fibroblasts, transfected with a recombinant DNA containing the neo gene and BK virus (BKV) early region, which expresses BPV large T antigen (TAg), show cytogenetic alterations characterized by dicentric chromosomes and other structural aberrations such as deletions, duplications, translocations, and ring chromosomes. Such alterations were absent or significantly less frequent in human fibroblasts transfected with a plasmid expressing only the neo gene. The chromosome damage in BKV-transfected cells was evident before the appearance of the morphologically transformed phenotype and therefore seems to be a primary effect of TAg expression in human cells. The specific pattern of chromosome aberrations suggests the prevalence of an indirect clastogenic effect, determined by the inhibition of p53 regulatory functions on genome stability by BKV TAg. Due to the widespread distribution of BKV in the human population and to the latent state of BKV DNA in many human organs, the clastogenic activity of BKV TAg may potentially participate in an oncogenic process involving BKV latently infected cells.

Establishment and characterization of two new cell lines derived from human metastatic breast carcinomas.

Two human cancer cell lines (MA 2 and MA 3) were established from pleural effusions of infiltrating ductal carcinomas of the breast. The lines were maintained in continuous monolayer culture with doubling times of 70 (MA 2) and 78 (MA 3) hr for more than two years and possessed extensively rearranged abnormal karyo-types with modal chromosome number of 83 (MA 2) and 81 (MA 3) and DNA index values of 1.65 and 1.77, respectively. No amplifications or rearrangements were evident in the c-myc, int-2, c-erb B2, c-Ha-ras, or hst 1 genes in MA 2 and MA 3 cell lines. The clinical histories of the patients from whom the cell lines were derived are reported and compared with the results observed in the cell lines in vitro. The presence of CEA, CA 15-3, and MCA tumor markers observed in the primary tumor tissues was retained by the established cell lines. While the primary tumor tissues were ER+/PgR borderline+ (MA 2) and ER-/PgR+ (MA 3), the MA 2 line was ER+/PgR- and the MA 3 line remained ER-/PgR+. The MDR P-glycoprotein was not expressed either in primary tumor tissues or in the respective cell lines. High expression of cytokeratins 7, 18, and 19 was evident by immunohistochemical analysis in each cell line. whereas cytokeratins 8 and 17 were poorly or not at all expressed. The treatment history of the patients from whom the cell lines were derived involved CMF followed six months later by novantrone and cisplatin plus VP 16 (MA 2) and FEC followed four years later by CMF (MA 3). The chemosensitivity pattern assay of the cell lines indicated that the MA 2 line was sensitive to doxorubicin, cisplatin, and vinblastine, whereas the MA 3 line was sensitive to doxorubicin and cisplatin. The characteristics of these cell lines indicate them to be a good experimental model to investigate breast cancer biology and anticancer drug response.

Branchio-oto (BO) syndrome and oculo-auriculo-vertebral phenotype: overlapping clinical findings in a child from a BO family.

A three-generation BO family is presented: the proband showed, in addition to branchio-oto malformations, a severe condition with growth retardation, mandibular hypoplasia and vertebral anomalies resembling the oculo-auriculo-vertebral (OAV) phenotype. This family study supports the hypothesis of Rollnick and Kaye that the OAV spectrum may represent, in some cases, an extreme component of the BOR syndrome. The finding has relevant implications for genetic counselling regarding both conditions.

Psychiatric disorder in a familial 15;18 translocation and sublocalization of myelin basic protein of 18q22.3.

Two related patients with similar clinical features consisting of a few dysmorphic signs and psychiatric disturbance were reported to have a partial trisomy of chromosomes 15(pter-q13.3) and 18(q23-qter) deriving from a familial translocation t(15;18). One patient is affected by bipolar disorder and the other by schizoaffective disorder. Both cases have a predominantly affective course; nevertheless, a clear diagnosis is difficult in the first patient, who is 15 years of age, and only a longitudinal course will allow us to establish a definite diagnosis. The possibility that these two pathologies belong to a single category is discussed, and the presence of a susceptibility locus on chromosome 18 is hypothesized. Cytogenetic data, FISH, and DNA studies indicate that the myelin basic protein (MPB) gene is not involved in the translocation, and localize it centromeric to the breakpoint on chromosome 18(q22.3). Thus, it is unlikely to be involved in the disease.