De Novo Large Deletion Leading to Fragile X Syndrome

Fragile X syndrome (FXS) is the most frequent cause of X-linked inherited intellectual disabilities (ID) and the most frequent monogenic form of autism spectrum disorders. It is caused by an expansion of a CGG trinucleotide repeat located in the 5'UTR of the FMR1 gene, resulting in the absence of the fragile X mental retardation protein, FMRP. Other mechanisms such as deletions or point mutations of the FMR1 gene have been described and account for approximately 1% of individuals with FXS. Here, we report a 7-year-old boy with FXS with a de novo deletion of approximately 1.1 Mb encompassing several genes, including the FMR1 and the ASFMR1 genes, and several miRNAs, whose lack of function could result in the observed proband phenotypes. In addition, we also demonstrate that FMR4 completely overlaps with ASFMR1, and there are no sequencing differences between both transcripts (i.e., ASFMR1/FMR4 throughout the article).

The role of AGG interruptions in the FMR1 gene stability: A survey in ethnic groups with low and high rate of consanguinity

Background

The prevalence and the role of AGG interruptions within the FMR1 gene in the normal population is unknown. In this study, we investigated the frequent of AGG loss, in one or two alleles within the normal population. The role of AGG in the FMR1 stability has been assessed by correlating AGG loss to the prevalence of premutation/full mutation in two ethnic groups differing in their consanguinity rate: high versus low consanguinity rate (HCR vs. LCR).

Methods

The CGG repeat allele size and AGG presence were measured in 6,865 and 6,204 females belonging to the LCR (5%) and HCR (>45%) groups, respectively, by Tripled‐Primed‐PCR technique.

Results

A lower prevalence of the premutation was observed in the HCR (1:158) as compared to the LCR group (1:128). No full mutation was found in the HCR females while in the LCR group the prevalence found was 1:1,149. Homozygosity rate was higher in the HCR population compared to the LCR group.The overall AGG loss was higher in the HCR population than in the LCR and increased with increased CGG repeat number in both ethnic groups.

Conclusions

Although we observed a significantly higher rate of homozygosity and AGG loss in the HCR group, this did not affect the prevalence of the premutation and full mutation in this population. Their prevalence was significantly lower than in the LCR population. Finally, we discuss whether the loss of AGG could be also a polymorphic event but not only a stabilizing factor.

TMEM70 deficiency: Novel mutation and hypercitrullinemia during metabolic decompensation

Respiratory chain disorders comprise a heterogeneous group of diseases that are the result of mutations in nuclear or mitochondrial genes. TMEM70 encodes a nuclear protein involved in the assembly of respiratory chain complex V. Although mutations in various genes can result in isolated complex V deficiency; TMEM70 mutations represent the most common reported etiology. TMEM70 deficiency is known to cause a syndrome of neonatal mitochondrial encephalocardiomyopathy, accompanied by elevated lactate and hyperammonemia. Elevated citrulline has been reported previously in different inborn errors of metabolism, although uncommonly associated with TMEMT70 deficiency. We present a series of two siblings diagnosed with TMEM70 deficiency, and describe hypercitrullinemia during decompensation as a new finding in this condition. The cause of hyperammonemia in TMEM70 deficiency was previously assumed to be related to carbamoyl phosphate synthase 1 deficiency, but our finding of hypercitrullinemia rules out this possibility. We thus propose a different etiology for the hyperammonemia seen in these patients.

Combined CNV, haplotyping and whole exome sequencing enable identification of two distinct novel EYS mutations causing RP in a single inbred tribe

Whole exome sequencing (WES) has become routine in clinical practice, especially in studies of recessive hereditary diseases in inbred consanguineous families, where homozygosity of a founder mutation is assumed. Multiple members of two consanguineous families of a single Bedouin tribe were diagnosed with apparently autosomal recessive/pseudo-dominant retinitis pigmentosa (RP). Affected individuals exhibited severe visual impairment with nyctalopia, marked constriction of visual fields, markedly reduced and delayed responses on electro-retinography (ERG) and eventual loss of central vision. Combined copy-number variant (CNV) analysis, haplotype reconstruction and WES of the kindred identified two distinct novel mutations in EYS (RP25): a p.(W1817*) nonsense mutation (identified through WES) and a large deletion encompassing 9 of the 43 exons, that was missed by WES and was identified through microarray CNV analysis. Segregation analysis of both mutations demonstrated that all affected individuals were either homozygous for one of the mutations, or compound heterozygous for both. The two mutations are predicted to cause loss of function of the encoded protein and were not present in screening of 200 ethnically-matched controls. Our findings of two distinct mutations in the same gene in a single inbred kindred, identified only through combined WES and microarray CNV analysis, highlight the limitations of either CNV or WES alone, as the heterozygous deletion had normal WES read-depth values. Moreover, they demonstrate pitfalls in homozygosity mapping for disease-causing variant identification in inbred communities.

Clonal evolution through genetic bottlenecks and telomere attrition: Potential threats to in vitro data reproducibility

Tissue cultures of immortalized human cells, also known as established cell lines, are broadly accessible and cost-efficient tools for biomedical research. We here review potential genetic sources of systematic error in cell line experiments due to clonal evolution in vitro. In particular, the authors highlight alterations in telomere function over prolonged culture and population bottlenecks, respectively, as two commonly overlooked phenomena that can result in significant alterations in cell line genotypes over just one or a few passages in vitro. These alterations may include changes in mutation status of oncogenes and large scale chromosomal imbalances. We introduce a simple list of factors to be avoided in order to reduce the risk of data misinterpretation due to clonal evolution, including unacknowledged in vitro selection pressures, prolonged culture per se, harsh population size reductions, experiments at early phases after establishment, and the employment of cell lines not sufficiently analyzed by high resolution genetic techniques.

Can bone marrow cellularity help in predicting prognosis in myelodysplastic syndromes?

OBJECTIVES

To ascertain the relevance of bone marrow cellularity (BMC) to the interpretation of blast percentage (blast%) in MDS prognostication.

METHODS

We compared survival prediction based on blast% adjusted to different levels of cellularity, compared to the survival based on the original IPSS-R blast% grouping.

RESULTS

We analyzed 355 consecutive MDS patients. Cellularity, in and of itself or its interaction with blast%, was not associated with overall survival (OS). In a small subset of patients with a hypercellular marrow (15%; n = 26), dismal prognosis was observed at lower levels of blast%. For these cases OS was similar to higher IPSS-R blast groups. For example, within the Intermediate group (blast% 5%-10%), those with a hypercellular marrow and >6% blasts had an OS of 10 m similar to 16 m in the High (blast% 10%-19%) blast group. These changes did not translate into a significant improvement in overall prognostic power of a cellularity-adjusted IPSS-R (C index 0.71 vs. 0.70).

CONCLUSION

Adjusting blast% to cellularity did not improve prognostication. However, within IPSS-R-defined blast groups, a small subset of patients with relatively higher blast% and hypercellularity may have a worse prognosis than expected.

Prenatal Diagnosis of Fragile X: Can a Full Mutation Allele in the FMR1 Gene Contract to a Normal Size?

Here we describe a case of a prenatal diagnosis of a male fetus that inherited the unstable allele from his full mutation mosaic mother (29, 160, >200 CGG repeats) reduced to a normal size range (19 CGG repeats). Haplotype analysis showed that the fetus 19 CGG repeats allele derived from the maternal unstable allele which was inherited from his maternal grandmother. No size mosaicism was detected by testing the DNA from in vitro cultured samples, including seventh passage culture as well as from two amniocentesis samples. Sequence analysis confirmed that the allele was 19 CGG repeats long. Methylation assay showed no methylation. Although none of the techniques used in this study can provide with absolute certainty the diagnosis, the results strongly indicate the presence in the fetus of an allele with a CGG repeat number in the normal range. Because this is a prenatal diagnosis case, the crucial question is whether the 19 CGG allele derived from the maternal unstable expanded allele, which contracted to the normal range, became a normal stable allele or a normal unstable allele which could expand in the next generation. It is also possible that allele size mosaicism of the FMR1 gene that went undetected exists. Because this is a prenatal diagnosis case, we cannot with certainty exclude the presence of an undetected expanded allele of the FMR1 gene, in addition to the 19 CGG allele derived from an unstable expanded allele, which contracted to the normal range.

Oral Mucoceles in Children--Analysis of 56 New Cases

BACKGROUND

Mucoceles are common cystic lesions of the oral mucosa. Extravasation mucoceles (EMs) are mainly found in the lower lip of young patients, whereas retention mucoceles (RMs) are usually located in the cheek or palate of older patients. This study was undertaken to more fully characterize the clinicopathologic features of mucoceles in pediatric patients.

METHODS

The records of 56 pediatric patients with mucoceles were included in the study. Age, sex, history of trauma, intraoral site, size, and method of treatment were evaluated. Histopathologically the lesions were classified as being EMs or RMs.

RESULTS

The age range was 1.5 to 16 years (mean age 11.2 yrs). Of the 56 patients, 24 (43%) were males and 32 (57%) were females, with a male:female ratio of 1:1.33. A history of trauma was recorded in 32 (57%) patients of the lower lip. The intraoral sites were the lower lip (38 [68%]), tongue (10 [18%]), and floor of the mouth (8 [14%]). Of the 56 patients, 44 (79%) were EM and 12 (21%) were ranulas. No RMs were found. Mucoceles ranged from 0.3 to 3.8 cm in diameter (mean 0.9 cm). The treatment of EMs was surgical excision. Cryosurgey, electrosurgery, and carbon dioxide laser were also used.

CONCLUSION

In contrast to adults, where EM and RM types can be found, among children all cases are of the EM type. The disparate site and age incidences of EMs and RMs of the oral mucosa suggest that these two types are not related and possibly have a different etiopathogenesis.

Can cell proliferation of umbilical cord blood cells reflect environmental exposures?

Environmental hazards were shown to have an impact on cell proliferation (CP). We investigated CP of lymphocytes in umbilical cord blood in relation to prenatal environmental exposures in a sample of 346 Arab-Bedouin women giving birth in a local hospital. Information on subjects' addresses at pregnancy, potential household exposures and demographical status was collected in an interview during hospitalization. This population is usually featured by high rates of neonatal morbidity and multiple environmental exposures, originating from the local industrial park (IP), household hazards and frequent male smoking. A geometric mean CP ratio 2.17 (2.06; 2.29), and was high in women residing in a direction of prevailing winds from the local IP (p value = 0.094) and who gave birth during fall-winter season (p value = 0.024). Women complaining on disturbing exposure to noise had lower CP (p value = 0.015), compared to other women. CP was not indicative of neonatal morbidity. However, our findings suggest that CP of umbilical cord might be modified by environmental exposures. A long-term follow-up of the children is required to assess their developmental outcomes.

Association between prenatal exposure to metals and neonatal morbidity

An association between prenatal exposure to (semi-)metals and of neonatal morbidity was assessed by introducing an oxidative stress as a possible intermediate step. An oxidative stress was measured by cell proliferation (CP) ratio in umbilical cord blood cells. Urine samples of 18 out of 58 enrolled women (31%) were positive for (semi-)metals; 25.9% of women were positive for aluminum (Al). The CP ratio was higher (1) in subjects with Al, (2) in mothers to newborns diagnosed as small-for-gestational age (p value = .052), (3) neonates that weighed less (p value = .079), and (4) in women who experienced repeated abortions (p value = .049). Our findings suggest the possibility of metal-induced oxidative stress.

[Introsseous schwannoma of the mandible]

Schwannoma is a benign neoplasm originating from the neural sheath and occuring most often in the soft tissues of the head and neck. Intraosseous schwannoma (IS) is extremely rare, most commonly occurring in the mandible. This paper documents a case of IS and the histopathology, karyotyping, CT, and MRI in the diagnostic work-up. Histologically it was a classic schwannoma. The karyotype was normal. CT demonstrated destruction of the mandibular canal while MRI detected encasement of the inferior alveolar nerve by the tumor, and consequently the need to resect the nerve together with the tumor. Using CT and MRI, the morbidity associated with the anticipated surgery can precisely be determined preoperatively.

Study of plasma-induced peripheral blood mononuclear cells survival using Fourier transform infrared microspectroscopy

Components present in the acellular fraction of blood influence the blood cell survival and function and the response to biotic and abiotic factors. Human plasma and sera have been used as therapeutic agents and are known to increase cell survival. White blood cells in normal blood are exposed to plasma components in vivo, but the effect of such plasma components in vitro on adherent peripheral blood mononuclear cells (PBMCs) that includes monocytes has not been fully investigated. We cultured human PBMCs with autologous plasma and observed structural variation due to plasma addition in PBMCs along with increased cell survival. Light microscopy of the cells showed increased granularity in plasma-treated cells. Fourier transform infrared (FTIR) spectroscopy was used to elucidate the possible mechanism by studying the changes in the biochemical composition of the cells that explained the observations. FTIR spectroscopy of plasma-treated cells show altered spectral pattern in the mid-IR region, indicating increased phospholipid levels. Heat-stable components in the plasma possibly increase the differentiation of PBMCs, as evident by increased phospholipid metabolism. The data suggest that plasma-stimulated membrane biogenesis may contribute to PBMC survival by inducing them to differentiate into antigen presenting cells (APCs) like macrophages and dendritic cells.

Solitary fibrous tumor of the buccal vestibule: report of two cases

Solitary fibrous tumor (SFT) is a rare benign tumor that occurs most frequently in the pleura. It is considered rare in the maxillofacial area. Two new cases of SFT of the buccal vestibule are reported. The previously reported cases of oral SFT are reviewed. The tumors were composed of spindle-shaped cells that were arranged haphazardly and were positive for CD-34, BCL-2, CD-99 and vimentin. Although rare, SFT should be included in the differential diagnosis of oral soft tissue tumors. The clinical presentation and imaging can provide the clinician a better tool for preoperative diagnosis.

Pleomorphic adenoma occurring outside the submandibular gland: a case report of an accessory submandibular gland

The accessory submandibular gland is a rare anatomic variant and the incidence of pathology reported within an accessory submandibular gland is even rarer. This report describes the case of a 22-year-old woman who presented with a slowly enlarging mass in the submandibular triangle, which on ultrasound examination suggested that it was close to, but not arising from, the submandibular gland. Fine-needle aspiration cytology was consistent with a pleomorphic adenoma. At surgery, the tumor was found to be entirely separate from the submandibular gland. This case presents an extremely rare occurrence of an accessory submandibular gland and, to the authors' knowledge, is the first report of a pleomorphic adenoma occurring within an accessory submandibular gland.

Cutaneous sinus tract of dental origin in children-a report of 28 new cases

Little is known about the characteristics of cutaneous sinus tract (CST) of dental origin in children. 28 cases of CST of dental origin in children were evaluated. Age, sex, site of skin lesion, duration until diagnosis, teeth involved, etiology, treatment, and outcome were recorded. The last dental care visit was also recorded. The mean age was 10.25 years (range 4-16). The male to female ratio was 1:1.74. The mandibular-submandibular area was the most common site of skin lesions. The mandibular first molar was the most involved tooth, followed by the mandibular incisor. Caries was the most common etiology. The mean duration of lesions until correct diagnosis was 6.5 months (range 0.3-12 mos). The treatment was root canal therapy or extraction. After appropriate dental treatment, CSTs resolve rapidly. Surgical revision of the scars were indicated in eight (29%) patients, to provide better cosmetic results. In these patients, the duration of lesions were longer. Preventive dental care, as indicated by last dental care visit, was poor. CST in children is different from that in adults in terms of sites of skin lesions, duration of lesions, and involved tooth and similar to that in adults in terms of etiology and treatment modality. Early treatment of the dental infection may cause healing of the cutaneous lesion spontaneously, without a scar.

O-linked β-N-acetylglucosaminylation (O-GlcNAcylation) in primary and metastatic colorectal cancer clones and effect of N-acetyl-β-D-glucosaminidase silencing on cell phenotype and transcriptome

O-linked β-N-acetylglucosamine (O-GlcNAc) glycosylation is a regulatory post-translational modification occurring on the serine or threonine residues of nucleocytoplasmic proteins. O-GlcNAcylation is dynamically regulated by O-GlcNAc transferase and O-GlcNAcase (OGA), which are responsible for O-GlcNAc addition and removal, respectively. Although O-GlcNAcylation was found to play a significant role in several pathologies such as type II diabetes and neurodegenerative diseases, the role of O-GlcNAcylation in the etiology and progression of cancer remains vague. Here, we followed O-GlcNAcylation and its catalytic machinery in metastatic clones of human colorectal cancer and the effect of OGA knockdown on cellular phenotype and on the transcriptome. The colorectal cancer SW620 metastatic clone exhibited increased O-GlcNAcylation and decreased OGA expression compared with its primary clone, SW480. O-GlcNAcylation elevation in SW620 cells, through RNA interference of OGA, resulted in phenotypic alterations that included acquisition of a fibroblast-like morphology, which coincides with epithelial metastatic progression and growth retardation. Microarray analysis revealed that OGA silencing altered the expression of about 1300 genes, mostly involved in cell movement and growth, and specifically affected metabolic pathways of lipids and carbohydrates. These findings support the involvement of O-GlcNAcylation in various aspects of tumor cell physiology and suggest that this modification may serve as a link between metabolic changes and cancer.

Cytogenetics of primary embryonal rhabdomyosarcoma of the cheek

Rhabdomyosarcoma (RMS) is the most common malignant soft tissue tumour of childhood and has two main subtypes: embryonal and alveolar. The embryonal subtype accounts for most cases in the genitourinary tract and head and neck. Oral presentations are rare, and mainly in the tongue, palate, or cheek. Cytogenetically, alveolar RMS is characterised by the translocation t(2;13)(q35;q14), which plays an important part in diagnosis, but no consistent and unique genetic alterations have been identified in embryonal RMS. It is currently not known whether oral embryonal RMS is similar to those that arise from other sites, as only one cytogenetic report has been published to date. We present the case of a 9-year-old boy with embryonal RMS of the cheek, and discuss the cytogenetic alterations in his case.

Cystic lesions of the jaws - a clinicopathological study of 322 cases and review of the literature

Three hundred and twenty-two patients (192 male and 130 female) with cystic lesions of the jaw were successfully diagnosed and treated. One hundred and fifty-five (48%) were radicular cysts, 80 (25%) were dentigerous cysts, 23 (7%) were odontogenic keratocyst (=keratocystic odontogenic tumor), 19 (6%) were eruption cysts, 16 (5%) were traumatic bone cysts, and 29 (9%) were non-odontogenic cysts. There were 95 in the pediatric age group (1 month to 16 years) and 227 in the adult age group (17 years and older). Male to female ratio was 1 in the pediatric age group and 1.7 in the adult age group. The treatment modalities were: marsupialization, enucleation, enucleation with bone grafting, or resection. The distribution and characteristics of jaw cysts in children are different from those in adults. In children there is a relatively high rate of developmental cysts, whereas in adults the inflammatory cysts are more common. Following enucleation of a cystic jaw lesion, the entire surgical specimen and not only a biopsy specimen, should be examined histopathologically to prevent any possibility of an intramural squamous cell carcinoma that may be overlooked. The differences in prevalence of each type of jaw cyst during a lifetime may point toward a multifactorial polygenic pattern rather than a monogenic pattern.

[Cytogenetics of oral solid tumors]

The tumorigenesiss of oral solid tumors is still uncertain. The underlying mechanisms of epithelial or connective tissue proliferation are not yet fully understood. Also, the transformation of a benign tumor into malignant is obscure. Cytogenetics is the study of chromosome number and structure using a light microscope. Human chromosome nomenclature is based on An International System for Human Cytogenetic Nomenclature (ISCN). The normal human somatic cells have 46 chromosomes, including 22 pairs of autosomes and two sex chromosomes, XX in female and XY in male. The chromosome abnormalities can be numerical and structural. Both types can occur concurrently. Numerical abnormalities involve the loss and/or gain of a whole chromosome and can include both autosomes and sex chromosomes. Cells which have lost a chromosome are categorized as a monosomy, while those with an extra chromosome are trisomy. Structural abnormalities include translocations, deletions, inversions and insertions. Cancer, in its various forms is a result of genetic changes. This concept comes from the finding of chromosomal abnormalities. These abnormalities may arise as a consequence of random replication errors; exposure to carcinogens; or damaged DNA repair process. In clinical oncology, the study of chromosome abnormalities in solid tumors provides valuable information for the diagnosis, evaluating treatment response of metastatic cancer, marker for prognosis and targeted therapy. In tumors which histologic features overlap, cytogenetics plays an important role for diagnosis. Cytogenetics has also been used to monitor the surgical margins of the resection in head and neck carcinoma, where the histology was not definitive. The present report will focus on the role of cytogenetics in the diagnosis and prognosis of benign and malignant oral solid tumors.

Cytogenetics of jaw cysts - a pilot study

The pathogenesis of cysts that arise in the jaws is still not certain, and the underlying mechanisms of epithelial proliferation are not fully understood. Cysts of the jaw may involve a reactive, inflammatory, or neoplastic process. Cytogenetics, the study of the number and structure of chromosomes, has provided valuable information about the diagnosis, prognosis, and targeted treatment in many cancers, including oral squamous cell carcinoma. Cytogenetics can also provide information about the possible aetiology or neoplastic potential of a lesion, though to our knowledge no studies of this technique have been used for cysts in the jaws. In this pilot study we used cytogenetics in a series of 10 cysts (3 radicular, 4 dentigerous, 2 of the nasopalatine duct, and 1 dermoid). In all cases we found normal karyotypes. Further work and larger numbers are needed for a definitive study, but we can hypothesise from this pilot study that these cysts do not have cytogenetic aberrations and so have no neoplastic potential.

Primary intraosseous squamous cell carcinoma arising in an odontogenic cyst: a clinicopathologic analysis of 116 reported cases

PURPOSE

To review the literature on primary intraosseous squamous cell carcinoma (PIOSCC) associated with odontogenic cyst.

METHODS

All well-documented cases of PIOSCC published between 1938 and 2010 were collected. Only cases of PIOSCC arising from the lining of an odontogenic cyst, including the keratocystic odontogenic tumor, were selected. Age, sex, signs and symptoms, affected jaw, cyst type, treatment, histopathology, and outcome were recorded.

RESULTS

The mean age was 60.2 years (range 1.3-90). There were 80 (69%) men and 36 (31%) women. Mass and pain were the most common presenting symptoms. The mandible was affected in 92 (79%) patients and the maxilla in 24 (21%). It was a residual/radicular cyst in 70 (60%) patients and a dentigerous cyst or a keratocystic odontogenic tumor in the remaining 40%. The histopathology was well-differentiated SCC in 53 (46%) patients and moderately differentiated SCC in 47 (40%) patients. Fifty-three (46%) patients were treated with surgery alone and 44 (38%) with surgery and radiotherapy. Fifty-eight (62%) patients survived 2 years and 36 (38%) survived 5 years.

CONCLUSION

PIOSCC has a predilection for men (M/F ratio of 2.22:1), affects mainly adults in their 6-8th decades, occurs most frequently (79%) in the mandible, and is associated mainly with a residual/radicular cyst. Histologically, the well-to-moderately differentiated SCC was the most common. Surgery alone or combined therapy of surgery and radiation was the most common approach. The prognosis is 62% surviving 2 years and 38% 5 years.

Primary ciliary dyskinesia caused by homozygous mutation in DNAL1, encoding dynein light chain 1

In primary ciliary dyskinesia (PCD), genetic defects affecting motility of cilia and flagella cause chronic destructive airway disease, randomization of left-right body asymmetry, and, frequently, male infertility. The most frequent defects involve outer and inner dynein arms (ODAs and IDAs) that are large multiprotein complexes responsible for cilia-beat generation and regulation, respectively. Although it has long been suspected that mutations in DNAL1 encoding the ODA light chain1 might cause PCD such mutations were not found. We demonstrate here that a homozygous point mutation in this gene is associated with PCD with absent or markedly shortened ODA. The mutation (NM_031427.3: c.449A>G; p.Asn150Ser) changes the Asn at position150, which is critical for the proper tight turn between the β strand and the α helix of the leucine-rich repeat in the hydrophobic face that connects to the dynein heavy chain. The mutation reduces the stability of the axonemal dynein light chain 1 and damages its interactions with dynein heavy chain and with tubulin. This study adds another important component to understanding the types of mutations that cause PCD and provides clinical information regarding a specific mutation in a gene not yet known to be associated with PCD.

Oral lipoma: analysis of 58 new cases and review of the literature

Lipomas are common soft-tissue tumors but occur infrequently in the oral region. Here, we present 58 new cases of oral lipoma (OL), their clinical features, diagnostic workup, and management. The records of 58 patients with OL were reviewed. Demographic data, presenting symptoms, primary tumor site, histopathology, and clinical management were analyzed. Extraoral and intraosseous lesions were excluded. The patients were 29 men and 29 women with mean age of 59.7 years, range, 11 to 98 years. Tumor sites included the buccal mucosa (n = 31), tongue (n = 10), lip (n = 6), floor of the mouth (n = 6), and vestibule (n = 5). The mean tumor size was 2.1 cm (range, 0.3-5.0 cm). The mean tumor duration before excision was 2.6 years (31.2 months), ranging from 2 months to 12 years. Most common presenting symptom was an asymptomatic, circumscribed mass. Histologically, the tumors were classified as classic lipoma (n = 28), fibrolipoma (n = 19), intramuscular lipoma (n = 4), minor salivary gland lipoma (n = 2), angiolipoma (n = 2), and spindle cell lipoma (n = 3). A case of spindle cell lipoma affecting the lower lip that has not been described previously is presented. The provided treatment was surgical excision. Although uncommon, OL are most common in adults and very uncommon in children. No sex predilection was found. The buccal mucosa region is the most common site followed by the tongue. Classic lipomas are most common in the oral region and comprise 48% of the tumors. A case of spindle cell lipoma of the lower lip is reported. Its clinical, histologic, and cytogenetic workup is the first well-documented case. Further cytogenetic studies should be undertaken to learn more about the pathogenesis and tumorigenesis of OL.

Autosomal recessive hyponatremia due to isolated salt wasting in sweat associated with a mutation in the active site of Carbonic Anhydrase 12

Genetic disorders of excessive salt loss from sweat glands have been observed in pseudohypoaldosteronism type I (PHA) and cystic fibrosis that result from mutations in genes encoding epithelial Na+ channel (ENaC) subunits and the transmembrane conductance regulator (CFTR), respectively. We identified a novel autosomal recessive form of isolated salt wasting in sweat, which leads to severe infantile hyponatremic dehydration. Three affected individuals from a small Bedouin clan presented with failure to thrive, hyponatremic dehydration and hyperkalemia with isolated sweat salt wasting. Using positional cloning, we identified the association of a Glu143Lys mutation in carbonic anhydrase 12 (CA12) with the disease. Carbonic anhydrase is a zinc metalloenzyme that catalyzes the reversible hydration of carbon dioxide to form a bicarbonate anion and a proton. Glu143 in CA12 is essential for zinc coordination in this metalloenzyme and lowering of the protein-metal affinity reduces its catalytic activity. This is the first presentation of an isolated loss of salt from sweat gland mimicking PHA, associated with a mutation in the CA12 gene not previously implicated in human disorders. Our data demonstrate the importance of bicarbonate anion and proton production on salt concentration in sweat and its significance for sodium homeostasis.

Congenital insensitivity to pain: novel SCN9A missense and in-frame deletion mutations

SCN9Aencodes the voltage-gated sodium channel Na(v)1.7, a protein highly expressed in pain-sensing neurons. Mutations in SCN9A cause three human pain disorders: bi-allelic loss of function mutations result in Channelopathy-associated Insensitivity to Pain (CIP), whereas activating mutations cause severe episodic pain in Paroxysmal Extreme Pain Disorder (PEPD) and Primary Erythermalgia (PE). To date, all mutations in SCN9A that cause a complete inability to experience pain are protein truncating and presumably lead to no protein being produced. Here, we describe the identification and functional characterization of two novel non-truncating mutations in families with CIP: a homozygously-inherited missense mutation found in a consanguineous Israeli Bedouin family (Na(v)1.7-R896Q) and a five amino acid in-frame deletion found in a sporadic compound heterozygote (Na(v)1.7-DeltaR1370-L1374). Both of these mutations map to the pore region of the Na(v)1.7 sodium channel. Using transient transfection of PC12 cells we found a significant reduction in membrane localization of the mutant protein compared to the wild type. Furthermore, voltage clamp experiments of mutant-transfected HEK293 cells show a complete loss of function of the sodium channel, consistent with the absence of pain phenotype. In summary, this study has identified critical amino acids needed for the normal subcellular localization and function of Na(v)1.7.

Cystic lesions of the jaws in edentulous patients: analysis of 27 cases

In this retrospective study we reviewed the distribution, characteristics, and treatment of 27 cystic jaw lesions in edentulous patients, and compared these with 242 cysts in dentate patients. The mean age was 60 years (range 46-74), and the male:female ratio 4.4:1. The maxilla was more affected than the mandible, with radicular/residual cysts being the most common. Patients were treated by marsupialisation, enucleation, or enucleation with bone grafting. Edentulous men were at higher risk than women of developing cystic lesions in the maxilla. Patients who are edentulous alert us to the possibility that their general health may be compromised, and this should be kept in mind when planning treatment.

Familial neonatal isolated cardiomyopathy caused by a mutation in the flavoprotein subunit of succinate dehydrogenase

Cardiomyopathies are common disorders resulting in heart failure; the most frequent form is dilated cardiomyopathy (DCM), which is characterized by dilatation of the left or both ventricles and impaired systolic function. DCM causes considerable morbidity and mortality, and is one of the major causes of sudden cardiac death. Although about one-third of patients are reported to have a genetic form of DCM, reported mutations explain only a minority of familial DCM. Moreover, the recessive neonatal isolated form of DCM has rarely been associated with a mutation. In this study, we present the association of a mutation in the SDHA gene with recessive neonatal isolated DCM in 15 patients of two large consanguineous Bedouin families. The cardiomyopathy is presumably caused by the significant tissue-specific reduction in SDH enzymatic activity in the heart muscle, whereas substantial activity is retained in the skeletal muscle and lymphoblastoid cells. Notably, the same mutation was previously reported to cause a multisystemic failure leading to neonatal death and Leigh's syndrome. This study contributes to the molecular characterization of a severe form of neonatal cardiomyopathy and highlights extreme phenotypic variability resulting from a specific missense mutation in a nuclear gene encoding a protein of the mitochondrial respiratory chain.

Dependence of maternal serum [AFP]/[hCG] median ratios on age of gestation: comparison of trisomy 21 to euploid pregnancies

BACKGROUND

Current risk calculations for trisomy 21, which are based on multiples of median (MoM), do not take into account possible differences between euploid and trisomy 21 pregnancies that may develop with gestational age. In order to optimize the predictive value of screening tests, we calculated the ratio between maternal serum concentration of alpha-fetoprotein (AFP) and that of human chorionic gonadotropin (hCG) in euploid and in trisomy 21 pregnancies.

METHODS

The medians of the concentration ratios, [AFP]/[hCG] at 16-21 weeks of gestation, were plotted as a function of gestational age for 307 cases of trisomy 21 and were compared with the medians of 30 549 normal karyotype cases.

RESULTS

[AFP]/[hCG] ratio medians were independent of body weight and maternal age. There was a significant difference in the [AFP]/[hCG] ratio when comparing trisomy 21 and euploid pregnancies at each week. This difference became greater with advancing gestational age (P < 0.01).

CONCLUSION

There is a significant difference in ratios of [AFP]/[hCG] between euploid and trisomy 21 pregnancies, which may be used to improve detection rates of Down syndrome screening.

Translocation (12;14) and other chromosome abnormalities in squamous cell carcinoma of the tongue

Tongue squamous cell carcinoma (SCC) has an increasing incidence, a high morbidity rate, and a 50% 5-year survival rate. The prognosis of tongue SCC is poor compared to SCC originating at other sites in the oral cavity, because they represent different biological subentities. Cytogenetic studies of head and neck SCC showed more losses than gains of various chromosomes or chromosomal segments. Among the frequent alterations there are losses of -4, -10, -13, -14, -18, -19, -21, -22, gains of +7, +8, +9, +16, +18, +20, and isochromosomes i(1q), i(3q), i(5p), i(8q). We are unaware of cytogenetic reports describing t(12;14) in tongue SCC. This is a cytogenetic study of SCC of the tongue. Tongue biopsy tissue was minced and cultured in RPMI-1640 medium. Cells were fixed and stained, and cytogenetic analysis performed according to standard procedures. A clone with t(12;14) along with other random numerical chromosomal changes was found in a case of tongue SCC. The significance of t(12;14) in diagnosis or prognosis is not clear and should be further examined. Karyotyping of more tongue SCC cases will expand the knowledge regarding chromosomal aberrations in SCC and thus might shed light on the significance of t(12;14) shown in this study.

Derivative (22)t(3;22)(q12;p11.1) in desmoplastic medulloblastoma

Medulloblastoma is a malignant invasive embryonal tumor of the cerebellum, representing 15-30% of pediatric brain tumors. An i(17q) abnormality appears in 40% of medulloblastomas, and usually not as a sole aberration; however, cytogenetic data for medulloblastoma are limited. Cytogenetic work-up of tumors is an important tool for diagnosis and prognosis, and in some cases has led to the development of new therapeutic modalities. In the present case, cytogenetic analysis of a medulloblastoma revealed an unbalanced karyotype in all cells analyzed: 46,XY,der(22)t(3;22)(q12;p11.1). This sole unbalanced translocation led to partial trisomy of 3q. The significance of this finding and its role in the pathogenesis of medulloblastoma need further clarification.

McCune-Albright syndrome in a discordant monozygotic twin

BACKGROUND

McCune-Albright syndrome is a sporadic disorder characterized by polystotic fibrous dysplasia, pigmented patches of skin, and endocrinological abnormalities.

OBJECTIVES

To compare the genetic characteristics of the GNAS1 gene in a monozygotic pair of twins, one of whom was diagnosed with MAS while the other had no indication of the syndrome.

METHODS

We performed a molecular analysis of the GNAS1 gene in DNA extracted from peripheral blood cells and quantification of mRNA extracted from lymphoblastoid cells from both twins by quantitative real-time polymerase chain reaction.

RESULTS

Monozygosity of the twins was confirmed by typing them to four highly polymorphic microsatellites. Molecular analysis of the GNAS1 gene extracted from both twins did not reveal the cause of this discordance.

CONCLUSIONS

It is possible that the exact molecular mechanism for the MAS discordance can only be determined by sampling affected tissues.

Human plasma accelerates immortalization of B lymphocytes by Epstein-Barr virus

OBJECTIVE

Serum and plasma contain species-specific factors that modulate cell population growth and function, and that are required for proliferation of most cell cultures. Foetal calf serum (FCS) is the most common source of these growth factors. We studied the effect of human plasma (HP) on the immortalization process of B lymphocytes by Epstein-Barr virus (EBV) was studied.

MATERIALS AND METHODS

The effect of HP as compared to FCS was done through assessment of cell proliferation.

RESULTS

It was found that HP (autologous and non-autologous plasma) is more effective than FCS in generating lymphoblastoid cell lines, regardless of EBV status of the donors: 65% of HP-supplemented cultures developed into lymphoblastoid cell lines by 7-14 culture days, as compared to 16% of cultures with FCS. In addition, 6% of HP-supplemented cultures did not achieve becoming lymphoblastoid cell lines by day 35 in comparison to 94% of cultures with FCS. The higher proliferative effect of HP was not altered by heat inactivation or filtration. HP maintained its proliferative activity at 4 degrees C over 8 months, thus indicating that HP contains a stable growth factor(s), which accelerates B-lymphocyte immortalization.

CONCLUSION

The results support other studies that recommend the use of autologous plasma for tissue culture, mainly in the case of autologous transplantation. Furthermore, the use of HP allows preparation of lymphoblastoid cell lines from a small amount of peripheral blood in a shorter period of time and with a higher rate of success.

Acquired chromosome instability in the elderly--the effect of diepoxybutane

Aging and Alzheimer's disease (AD) have been the subject of many studies. It has been suggested that chromosomal alterations may be involved in the etiology and/or pathogenesis of ageing and AD. The purpose of the present study was to examine the effect of diepoxybutane (DEB) on lymphocyte chromosomal instability in the elderly. We examined lymphocytes cytogenetically with, as well as, without DEB treatment, in a group of 12 elderly (range of age 72-96 years), nine of them suffering from AD type. Without DEB treatment six of the donors expressed chromosomal instability in at least 6% of the analyzed cells. After treatment with DEB, lymphocytes showed an increase in the chromosomal instability in up to 20% of the analyzed in eight donors. The sex chromosomes were the main chromosomes involved in the acquired chromosomal abnormalities. It is not clear from this study whether this chromosomal instability is related to the AD. The significance of the involvement of sex chromosomes either in ageing or in AD, as well as, the question whether the chromosomal instability is the cause of or part of ageing processes, has to be addressed.

Solitary angiokeratoma of the tongue

Angiokeratoma is a rare cutaneous lesion. It can be either a generalized systemic form, presenting as multiple asymptomatic papules on the skin, associated with metabolic diseases or a solitary cutaneous form. Oral cavity involvement is more common in the systemic form, as a part of a more generalized cutaneous disease, but very rare in the localized form of angiokeratoma. A 45-year-old female presented with a painless lesion on the tongue of one months duration, which bled occasionally. On clinical examination, a lesion of approximately 5 mm in diameter was observed on the left surface of the tongue. The lesion was purple in color with a granulomatous appearance. There were no other changes in the oral mucosa. On dermatologic examination, no angiokeratomas were found, anywhere on the skin. The lesion was excised under local anesthesia. The histologic diagnosis was angiokeratoma. A case of a solitary angiokeratoma of the tongue is reported. We report here the third intra-oral case and the second case in the tongue with solitary angiokeratoma.

Lethal congenital contractural syndrome type 2 (LCCS2) is caused by a mutation in ERBB3 (Her3), a modulator of the phosphatidylinositol-3-kinase/Akt pathway

Lethal congenital contractural syndrome type 2 (LCCS2) is an autosomal recessive neurogenic form of arthrogryposis that is associated with atrophy of the anterior horn of the spinal cord. We previously mapped LCCS2 to 6.4 Mb on chromosome 12q13 and have now narrowed the locus to 4.6 Mb. We show that the disease is caused by aberrant splicing of ERBB3, which leads to a predicted truncated protein. ERBB3 (Her3), an activator of the phosphatidylinositol-3-kinase/Akt pathway--regulating cell survival and vesicle trafficking--is essential for the generation of precursors of Schwann cells that normally accompany peripheral axons of motor neurons. Gain-of-function mutations in members of the epidermal growth-factor tyrosine kinase-receptor family have been associated with predilection to cancer. This is the first report of a human phenotype resulting from loss of function of a member of this group.

Lethal contractural syndrome type 3 (LCCS3) is caused by a mutation in PIP5K1C, which encodes PIPKI gamma of the phophatidylinsitol pathway

Lethal congenital contractural syndrome (LCCS) is a severe form of arthrogryposis. To date, two autosomal recessive forms of the disease (LCCS and LCCS2) have been described and mapped to chromosomes 9q34 and 12q13, respectively. We now describe a third LCCS phenotype (LCCS3)--similar to LCCS2 yet without neurogenic bladder. Using 10K single-nucleotide-polymorphism arrays, we mapped the disease-associated gene to 8.8 Mb on chromosome 19p13. Further analysis using microsatallite markers narrowed the locus to a 3.4-Mb region harboring 120 genes. Of these genes, 30 candidates were sequenced, which identified a single homozygous mutation in PIP5K1C. PIP5K1C encodes phosphatidylinositol-4-phosphate 5-kinase, type I, gamma (PIPKI gamma ), an enzyme that phophorylates phosphatidylinositol 4-phosphate to generate phosphatidylinositol-4,5-bisphosphate (PIP(2)). We demonstrate that the mutation causes substitution of aspartic acid with asparagine at amino acid 253 (D253N), abrogating the kinase activity of PIPKI gamma . Thus, a defect in the phosphatidylinositol pathway leading to a decrease in synthesis of PIP(2), a molecule active in endocytosis of synaptic vesicle proteins, culminates in lethal congenital arthrogryposis.