Unusual Pattern of Inheritance of Haemoglobin-H Disease

A 35-year-old Sardinian woman with haemoglobin-H disease was found to have normal parents. This case with an unusual inheritance pattern is described, and its possible relevance for the current concepts of haemoglobin-H disease genetics is discussed.     

Tooth wear in the mixed dentition: a comparative study between children born in the 1950s and the 1990s

The aim of this study was to evaluate the degree of tooth wear in posterior deciduous teeth of 100 subjects in the second phase of mixed dentition who were born in the 1950s (50sG) and 100 subjects born in the 1990s (90sG). The degree of abrasion for each posterior deciduous tooth was scored ranging from 0 to 3. The comparison of the degree of abrasion showed significant differences between the two groups for all examined teeth (upper and lower deciduous canines and first and second primary molars) all of which appeared to be more abraded in the 50sG. The findings of the present study indicate that subjects who were born in the 1950s exhibited a significantly greater degree of tooth wear on the posterior deciduous teeth when compared with contemporary subjects, along with a well-recognized lower prevalence of malocclusions. Changes in dietary habits and a diet based on processed foods may be postulated as factors involved with a decrease of dental attrition in contemporary populations. An increase in the prevalence of mouth breathing (tested in the present study) appears to be associated with a decrease in tooth wear in the contemporary population as well.     

Genetics of SCID

Human SCID (Severe Combined Immunodeficiency) is a prenatal disorder of T lymphocyte development, that depends on the expression of numerous genes. The knowledge of the genetic basis of SCID is essential for diagnosis (e.g., clinical phenotype, lymphocyte profile) and treatment (e.g., use and type of pre-hematopoietic stem cell transplant conditioning). Over the last years novel genetic defects causing SCID have been discovered, and the molecular and immunological mechanisms of SCID have been better characterized. Distinct forms of SCID show both common and peculiar (e.g., absence or presence of nonimmunological features) aspects, and they are currently classified into six groups according to prevalent pathophysiological mechanisms: impaired cytokine-mediated signaling; pre-T cell receptor defects; increased lymphocyte apoptosis; defects in thymus embryogenesis; impaired calcium flux; other mechanisms. This review is the updated, extended and largely modified translation of the article "Cossu F: Le basi genetiche delle SCID ", originally published in Italian language in the journal " Prospettive in Pediatria " 2009, 156: 228-238.     

Dental arch dimensions in the mixed dentition: a study of Italian children born in the 1950s and the 1990s

The objective of this study was to compare the dental arch dimensions in the mixed dentition in two modern samples living in the same geographic area and separated by almost 35 years. A group of 83 subjects (39 boys and 44 girls) born between 1953 and 1959 (mean age: eight years and three months +/-15 months for the boys and seven years and 11 months +/-12 months for the girls) were compared with a group of 84 subjects (38 boys and 46 girls) born between 1990 and 1998 (mean age: eight years and eight months +/-12 months for the boys and eight years and four months +/-11 months for the girls). Measurements were taken on dental casts for posterior and anterior arch segments, intermolar and intercanine width, and mesiodistal size of incisors. The available anterior space in both arches and the posterior and anterior transverse dimensions were calculated. Groups were compared using a nonparametric test (Mann-Whitney U-test) for independent samples (P < .05). Results show that both boys and girls of 1990s showed significantly smaller maxillary intermolar width when compared with 1950s. Posterior transverse interarch discrepancy was significantly minor in girls of 1990s. The present population has a greater probability of developing a malocclusion as a consequence of the secular trend toward the reduction of the width of the upper arch.     

Activating PTPN11 mutations play a minor role in pediatric and adult solid tumors

The PTPN11 gene encodes SHP-2, a widely expressed cytoplasmic protein tyrosine phosphatase functioning as a signaling transducer. Germ-line PTPN11 mutations cause Noonan syndrome (NS), a developmental disorder characterized by an increased risk of malignancies. Recently, a novel class of activating mutations in PTPN11 has been documented as a somatic event in a heterogeneous group of leukemias. Because of the relatively higher prevalence of certain solid tumors in children with NS and the positive modulatory function of SHP-2 in RAS signaling, a wider role for activating PTPN11 mutations in cancer has been hypothesized. Here, we screened a number of solid tumors, including those documented in NS or in which deregulated RAS signaling occurs at significant frequency, for PTPN11 mutations. No disease-associated mutation was identified in rhabdomyosarcoma (n = 13), neuroblastoma (n = 32), melanoma (n = 50), thyroid (n = 85), and colon (n = 48) tumors; a novel missense change, promoting an increased basal phosphatase activity of SHP-2, was observed in one glioma specimen. Our data document that deregulated SHP-2 function does not represent a major molecular event in pediatric and adult tumors, further supporting our previous evidence indicating that the oncogenic role of PTPN11 mutations is cell-context specific.     

Biometric and magnetic resonance imaging assessment of dentofacial abnormalities in a case of Klippel-Trénaunay-Weber syndrome

Klippel-Trénaunay-Weber syndrome is characterized by cutaneous hemangioma, arteriovenous fistulas or varicosities (or both), and unilateral hypertrophy of hard and soft tissues with different localization. Klippel-Trénaunay-Weber syndrome represents a syndrome of interest for those in the fields of oral and maxillofacial radiology and pathology because of the high incidence of compromise of the orofacial area in affected patients. The patient reported here presents with all of the 3 characteristic signs of the syndrome. The somatic and facial hypertrophy is contralateral to angiomata. As revealed through the use of magnetic resonance imaging, the primary component of facial hypertrophy is adipic subcutaneous tissue. Statistical analysis of the dental dimensions revealed that teeth on the hypertrophic side are significantly larger than normal.     

Induction of distinct types of spontaneous electrical activities in mammary epithelial cells by epidermal growth factor and insulin.

Electrophysiological measurements of the membrane potentials of mouse mammary epithelial cells in primary culture revealed the presence of spontaneous-oscillating-hyperpolarizing potentials in cells incubated with epidermal growth factor. The hyperpolarizing potentials were 5-20 mV in amplitude and about 10 sec in duration. The peak height of the response was reduced by hyperpolarization, and the input membrane resistance decreased during the response. The response was probably due to activation of K+ channels. The latency period for the epidermal growth factor induction of the hyperpolarizing potential was approximately 3 hr. In contrast, insulin induced spontaneous-depolarizing potentials that were about 5 mV in amplitude and 1 sec in duration. The depolarizing potentials were attributed to activity of ion channels, since the peak height was dependent on the membrane potential and the depolarizing potential was accompanied by a decrease of input membrane resistance. The time lag for the induction of the depolarizing potential was 6-12 hr. Other hormones involved in mammary cell differentiation, such as cortisol and prolactin, neither induced the depolarizing potentials nor changed the induction of depolarizing potential by insulin. In addition, other growth factors, such as nerve growth factor and fibroblast growth factor, elicited no electrical activity.