Alberto Sensi

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 patients 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.

Familial occurrence of multiple pterygium syndrome: Expression in a heterozygote of the recessive form or variability of the dominant form?

We report on a case with apparently familial multiple pterygium syndrome (MPS). The proposita was a 3‐year‐old girl with classical symptoms of MPS. A careful clinical examination of the father disclosed the presence of few minor signs of the syndrome, including difficulty in opening the mouth widely, scoliosis, pectus excavatum, hands with slight cutaneous syndactyly, and bilateral single palmar creases. The radiograph of the hands disclosed malformed carpal bones and an altered metacarpal‐phalangeal pattern. The father shows limited symptoms, which has been reported before in the autosomal dominant form of MPS. However, it is also possible that he is showing a heterozygous state of the autosomal recessive form of MPS. In conclusion, we emphasize the importance of examining accurately the parents of a child who has classical MPS phenotype, even those with normal stature and an absence of facial anomalies.

A spectrum of LMX1B mutations in Nail-Patella syndrome: New point mutations, deletion, and evidence of mosaicism in unaffected parents

Purpose: Nail-Patella syndrome (MIM 161200) is a rare autosomal dominant disorder characterized by hypoplastic or absent patellae, dystrophic nails, dysplasia of the elbows, and iliac horn. In 40% of cases, a glomerular defect is present and, less frequently, ocular damage is observed. Inter- and intrafamilial variable expressivity of the clinical phenotype is a common finding. Mutations in the human LMX1B gene have been demonstrated to be responsible for Nail-Patella syndrome in around 80% of cases.Methods: Standard polymerase chain reaction and sequencing methods were used for mutation and single nucleotide polymorphism identification and control of cloned sequences. Array-CGH (Agilent, 244A Kit) was used for detection of deletions. Standard cloning techniques and the Snapshot method were used for analysis of mosaicism.Results: In this study, we present the results of LMX1B screening of 20 Nail-Patella syndrome patients. The molecular defect was found in 17 patients. We report five novel mutations and a ∼2 Mb deletion in chromosome 9q encompassing the entire LMX1B gene in a patient with a complex phenotype. We present evidence of somatic mosaicism in unaffected parents in two cases, which, to our knowledge, are the first reported cases of inheritance of a mutated LMX1B allele in Nail-Patella syndrome patients from a mosaic parent.Conclusion: The study of the described case series provides some original observations in an “old” genetic disorder.

Genetic syndromes involving hearing

OBJECTIVE The fundamental processes involved in the mechanism of hearing seem to be controlled by hundreds of genes and hereditary hearing impairment may be caused by a large variety of genetic mutations in different genes. Approximately 150 loci for monogenic syndromic and non-syndromic hearing impairment (HI) disorders have been mapped to the human genome. The identification of these genes and functional analysis of the proteins they encode, are paving the way towards a better understanding of the physiology and pathophysiology of the auditory system. To date, approximately 50 causative genes have been identified. METHODS The clinical and neuroradioldical findings of syndromal hearing impairment are analysed. RESULTS This paper presents an updated report on genetic syndromes in which a hearing impairment is involved, with a particular attention to the ones associated with external ear and craniofacial malformations. CONCLUSIONS Concepts in human genetics are rapidly evolving together with technologies. The concept itself of gene is changing. A genetic diagnosis of syndromal hearing impairment has many practical consequences: it can implies specific prognosis, specific management, specific recurrence risk in relatives and, if the diagnosis is confirmed at the molecular level, possibility of a specific early prenatal diagnosis for severe syndromes. It is important to highlight the necessity that the pediatric otolaryngologist must have a close collaboration with a clinical geneticist and a neuroradiologist.

Mosaic 22q13 deletions: evidence for concurrent mosaic segmental isodisomy and gene conversion

Although 22q terminal deletions are well documented, very few patients with mosaicism have been reported. We describe two new cases with mosaic 22q13.2-qter deletion, detected by karyotype analysis, showing the neurological phenotype of 22q13.3 deletion syndrome. Case 1 represents an exceptional case of mosaicism for maternal 22q13.2-qter deletion (45% of cells) and 22q13.2-qter paternal segmental isodisomy (55% of cells). This complex situation was suspected because cytogenetic, FISH and array-CGH analyses showed the presence of an 8.8 Mb mosaic 22q13.2-qter deletion, whereas microsatellite marker analysis was consistent with maternal deletion without any evidence of mosaic deletion. Molecular analysis led to the definition of very close, but not coincident, deletion and uniparental disomy (UPD) break points. Furthermore, we demonstrated that the segmental UPD arose by gene conversion in the same region. In Case 2, mosaicism for a paternal 8.9 Mb 22q13.2-qter deletion (73% of cells) was detected. In both patients, the level of mosaicism was also verified in saliva samples. We propose possible causative mechanisms for both rearrangements. Although the size of the deletions was quite similar, the phenotype was more severe in Case 2 than in Case 1. As maternal UPD 22 has not been generally associated with any defects and as the size of the deletion is very similar in the two cases, phenotype severity is likely to depend entirely on the degree of mosaicism in each individual.

Cytogenetic and array CGH characterization of an intrachromosomal complex rearrangement of 4q in a patient with a 4q-phenotype.

We report on a 3‐year‐old child who presented a de novo rearrangement of chromosome 4, detected on GTG banding and characterized by array CGH and FISH, as a complex intrachromosomal rearrangement with three deletions: del(q32.1q32.2), del(q33q34.1), del(q35.2), one tandem duplication dup(q34.3q35.1) and short normal regions in between. The study of karyotype–phenotype correlations in this and other patients with deletions of 4q suggests 4q33q34.1 as a candidate region for 4q‐syndrome and for craniofacial development.

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. Copyright

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 lines cytosol than in the patients 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.

Deficiency of neutrophil membrane antigen detected by monoclonal antibody in rheumatoid arthritis

Monoclonal antibodies (mAbs) against cell surface antigens and receptors are instrumental in defining specific membrane markers. mAbs GF26.7.3 and MF25.1 against human neutrophils modulated the activation mechanism of superoxide anion production induced by formyl‐peptide and PMA in all subjects. However, treatment with mAb MF 25.1 binds is absent in rheumatoid conditions. This confirms our previous data showing that defective expression of membrane components is associated with neutrophil dysfunction.