Transmission ratio distortion in the spinal muscular atrophy locus: data from 314 prenatal tests.

BACKGROUND: Spinal muscular atrophy (SMA) is a recessive neurodegenerative disorder characterized by the loss of alpha-motor neurons in the spinal cord and subsequent death of motor neuron cells. SMA occurs with a frequency of 1 in 6,000 live births, with a carrier frequency of 1 in 40, and is a leading genetic cause of infant mortality. SMA is caused by loss or mutation of the telomeric survival motor neuron gene (SMN1), which is deleted in almost 94% of SMA patients OBJECTIVE: To analyze the transmission ratio at the SMA locus, examining the segregation of the SMN1-deleted alleles in 314 fetuses from carrier parents who requested prenatal testing for the disease. METHODS: Prenatal diagnosis of SMA in families at 25% risk of the disease has been performed on chorionic villous sampling specimens, through direct detection of the SMN1 gene mutation and linkage analysis using microsatellite markers from the 5q13 region. Analysis of the genotypic/allelic frequencies of the SMN1 gene was performed using the chi2 test, assuming a recessive mendelian inheritance. RESULTS: Of 314 fetuses analyzed, 95 were homozygous for the wild-type allele (30.3%), 154 were carriers (49.0%), and the remaining 65 were homozygous for the mutated allele (20.7%). Statistical analysis demonstrated that proportion of fetuses predicted with SMA is lower than 25% expected for a recessive disorder, resulting in a transmission rate of the SMN1-deleted allele deviant from the 50% expected in a random the segregation of a mendelian tract (p = 0.016) CONCLUSIONS: This is the first study to evaluate the genotypic frequencies at the spinal muscular atrophy (SMA) locus based on data derived from prenatal analysis, which are not subject to ascertainment bias. The analysis showed a transmission ratio distortion at the SMA locus in favor of the SMN1 wild-type alleles.

Facial hemangioma and malformation of the cortical development: a broadening of the PHACE spectrum or a new entity?

Facial hemangioma is usually isolated but its association with craniocervical arterial anomalies and structural brain malformations is well known. The acronym PHACE syndrome (posterior fossa malformation, facial hemangiomas, arterial anomalies, cardiac/aortic anomalies, and eye abnormalities) has been used to indicate that disorder in which brain anomalies are mainly represented by the Dandy-Walker malformation. We report on a 10-month-old boy affected by facial hemangioma and a complex cortical dysplasia located in the left frontal region. The lesion was characterized by a deeply infolding pachygyric cortex and a band of gray matter lining the wall of the lateral ventricle. The entire left cerebral hemisphere appeared hypoplastic. No anomalies of the posterior fossa structures or cardiac/aortic malformations were present. An overlapping clinical/pathological pattern was previously reported in another patient with facial hemangioma and cerebrovascular anomalies. These observations seem to indicate that the facial hemangiomas may be associated with disorders of the cortical development.

The epidemiology of atopic dermatitis in Italian schoolchildren.

BACKGROUND: Atopic dermatitis (AD) is common in children in industrialized countries. Only one large population study on its prevalence has been conducted in Italy, based on self-report questionnaire. The present study was designed to estimate the prevalence of AD in schoolchildren in Italy by dermatologists' assessment and by UK Working Party criteria, and to investigate associated symptoms and factors. METHODS: Cross-sectional survey on a random sample of 9-year-old schoolchildren from seven Italian cities. Children were examined by experienced dermatologists. Parents and teachers answered standardized questionnaires. RESULTS: Of the 1369 children examined, 88 had a diagnosis of AD, with an estimated point prevalence of 5.8% (95% CI 4.5-7.1) in the reference population. The reported lifetime prevalence was 15.2 (95% CI 12.2-18.2) for AD, 11.9% (95% CI 9.0-14.8) for asthma, and 17.6% (95% CI 14.6-20.7) for rhino-conjunctivitis. The strongest associated factor was the presence of AD in at least one parent. No association of AD with maternal smoking during pregnancy, birth weight, maternal age at the time of the child birth and breast-feeding was observed. The environmental characteristics of the house and the school did not correlate with the prevalence of AD. Episodes of lower respiratory tract infections were associated with asthma, and to a lower extent also with AD and rhinitis. CONCLUSIONS: The prevalence of doctor-diagnosed AD in Italian schoolchildren is comparable to those reported for other developed countries. Family history of atopy was the single most important associated factor, while the complex interplay of environmental factors remains to be elucidated.

Progression of mycosis fungoides is associated with changes in angiogenesis and expression of the matrix metalloproteinases 2 and 9.

Changes in angiogenesis and expression of extracellular matrix-degrading enzymes have been substantiated during progression of solid tumours, whereas information on haematological tumours remains circumstantial. In this study, 57 biopsies of mycosis fungoides (MF), a haematological tumour of T-cell lineage, were investigated immunohistochemically for the extent of angiogenesis, and by in situ hybridisation for the expression of matrix metalloproteinases 2 (MMP-2, collagenase A) and 9 (MMP-9, collagenase B). The biopsies we grouped according to the stage of progression: patch-->plaque-->nodular (most advanced). The extent of angiogenesis, as microvessel area, of MF lesions as a whole was significantly higher than that of normal uninjured skin, used as a control. When the stages of MF progression were compared, the values of MF patch stage overlapped that of control skin, while values were significantly higher in the plaque stage and even higher in the nodular stage. In these stages, microvessels were widely scattered in the tumour tissue, in close association with tumour cells, and they frequently displayed arborisation and microaneurysmatic dilation. In contrast, in the patch stage microvessels were irregularly distributed around the tumour aggregates, and arborisation or dilated structures were only rarely seen. The expression of MMP-2 and MMP-9 mRNAs underwent significant upregulation in relation to advancing stage. Indeed, the upstaging was significantly associated with higher proportions of lesions positive for each mRNA or for both, and with lesions with the greatest intensity of expression for each mRNA. Besides tumour cells, the MMP-2 mRNA was expressed by microvascular endothelial cells of intratumour and peri-tumour vessels, and by fibroblasts which were especially abundant in the stroma adjacent to the tumour nodules. The MMP-9 mRNA was found to be present in a subset of tissue macrophages which were more frequently located in close vicinity to the tumour nodules. In contrast, in control skin, a weak positivity for the MMP-2 mRNA in very few microvascular endothelial cells and no signal for the MMP-9 mRNA were observed. These in situ data suggest that angiogenesis and degradation of the extracellular matrix occur simultaneously during MF progression. They imply that interaction between tumour cells and their microvasculature are all the more likely to occur during progression, occasionally with the contribution of tumour-associated stromal cells.

[Epidermal hamartoma and blaschkitis in an adult]. / Hamartome épidermique et blaschkite de l'adulte homolinéaires.

INTRODUCTION: Many inherited skin diseases and nevus malformations are distributed according to the Blaschko's lines. Some inflammatory skin diseases are also distributed according to these lines. OBSERVATION: In 1989 a 49-year-old woman presented with an epidermal nevus affecting the left hand and leg from the infancy. In 1994, inflammatory, linear papules occurred on the left leg, obscuring and continuing the previous lesions, on the left thigh and on the left clavicular region. On light microscopy, spongiosis of the epidermis and an infiltrate of lymphocytes and histiocytes in the superficial dermis were shown. Subintrant crops of new inflammatory lesions occurred for a period of two years, whereas the nevus lesions of the left hand persisted unchanged. These findings led to the final diagnosis of blaschkitis associated to epidermal nevus on the same Blaschko's lines. DISCUSSION: The distribution of a skin disease according to the Blaschko's lines underlines the presence in the affected skin of a mutant clone, with a different genetic material as compared with the normal skin. An early mutation giving raise to a mutant clone and affecting the left hemibody could be hypothesized in our case. The mutation probably involved a pleiotropic gene. The latter initially was responsible for thickening of the skin. Moreover, the mutation was also responsible for a particular proneness towards an exogenous factors, able to induce a persistent inflammatory skin eruption following the same lines.

Pyogenic granuloma stimulates angiogenesis in the chick embryo chorioallantoic membrane.

Ten samples of pyogenic granuloma and 10 of normal skin from age- and sex-matched controls were grafted onto the chick embryo chorioallantoic membrane (CAM) to investigate their possible angiogenic activity. The angiogenic response in pathological and control implants was assessed on histologic sections by a planimetric point-count method 4 days after grafting. The CAM mast cells were also quantified. The vascular counts in the area underlying the pyogenic granuloma were four times higher than those of normal skin. A higher number of mucosa-like mast cells was detected in the intermediate mesenchyme of the CAM in pathological samples in comparison to controls. Pyogenic granuloma may promote angiogenesis leading to release of several angiogenic factors. The role played in angiogenic response by the inflammatory cells, mainly mast cells, forming the perilesional infiltrate was supported by this study.

Herpes gestationis with transient bullous lesions in the newborn.

A case of severe bullous dermatosis in the newborn son of a mother with herpes gestationis is reported. Bullous lesions appeared in the child about 2 hours after delivery and regressed completely without specific treatment by the end of the first month, leaving numerous epidermal cysts. The immunologic phenomena were both qualitatively and quantitatively comparable to those obtained in the mother, i.e., deposition of complement (C3) and smaller amounts of IgG at the dermo-epidermal junction of the affected skin. A transient increase of the total serum IgE was demonstrated in the mother, while the serum IgE level in the newborn was less than 5 U/ml. The pathogenetic role of IgG autoantibodies in herpes gestationis and, more generally, in autoimmune diseases is discussed.

Congenital self-healing histiocytosis.

In a typical case of congenital self-healing histiocytosis of the Hashimoto-Pritzker type, the results of an ultrastructural examination of a nodule of a 30-day-old patient showed that about 25% of the cells contained unique phagosomes but no regularly laminated bodies. This case of congenital self-healing histiocytosis is an example of concurrent proliferation of two types of histiocytes (one with and one without Langerhans' granules). Since transitional forms were not observed, this finding might indicate the existence of congenital, self-healing forms of histiocytosis X.

A case of hibernoma in a child.

A rare case of hibernoma about the nipple in a 9-year-old boy is presented: the tumour was peculiar not only for the age and region, but also for its superficial, subepidermal site.

Immunity in tumours of the skin. Studies on cell-mediated immune reactions.

Cell-mediated immunity (CMI) was investigated in a series of patients with epithelial tumours of the skin and with Kaposi's sarcoma. In all 53 patients the peripheral blood lymphocyte count showed no substantial difference from the control values. The blasts count after phytohaemagglutinin stimulation in 30 patients ranged from 40-50% with no noticeable difference from the control values. Intradermal tests with the staphylococcal antigen, PPD-tuberculin and streptokinase-streptodornase carried out in 59 patients proved negative in a significant number of cases, mainly those of Kaposi's sarcoma. The non immune inflammatory response to chemical irritant (benzalkonium chloride) was more often negative (17 of 59 cases) than in controls (5 of 30 subjects). The DNCB sensitization test carried out in 28 patients was negative in 5 cases (2 cases of late basal-cell epithelioma, 2 cases of advanced squamous-cell carcinoma and 1 case of Kaposi's sarcoma). The findings do not thus indicate the presence of a gross CMI defect in the material studied, which would be borne out by all the tests employed. The sometimes discordant results of the various tests suggest the existence of partial CMI defects in certain tumours, but mainly in Kaposi's sarcoma. Such partial defects, encountered even in early neoplasms, coexist, in some cases, with failure of inflammatory response to chemical irritants.