The putative forkhead transcription factor FOXL2 is mutated in blepharophimosis/ptosis/epicanthus inversus syndrome.

In type I blepharophimosis/ptosis/epicanthus inversus syndrome (BPES), eyelid abnormalities are associated with ovarian failure. Type II BPES shows only the eyelid defects, but both types map to chromosome 3q23. We have positionally cloned a novel, putative winged helix/forkhead transcription factor gene, FOXL2, that is mutated to produce truncated proteins in type I families and larger proteins in type II. Consistent with an involvement in those tissues, FOXL2 is selectively expressed in the mesenchyme of developing mouse eyelids and in adult ovarian follicles; in adult humans, it appears predominantly in the ovary. FOXL2 represents a candidate gene for the polled/intersex syndrome XX sex-reversal goat.

[Occupational and environmental cancer in southern Sardinia: a survey on ten years of hospitalizations]. / Tumori ad elevata frazione eziologica occupazionale o ambientale nella ASL di Cagliari: un' analisi di 10 anni di ricoveri.

Based on hospital discharges in 1001-2010, we calculated risk of tumours with an elevated occupational and environmental etiological fraction by health district of residence within the Local Health Unit (LHU) N. 8 of Sardinia. With reference to the age and gender-specific hospitalization rates of the whole LHU, residents in the urban Cagliari health district showed an excess risk of haemolymphopoietic cancer (RR = 1.07; 95% CI 1.03-1.12) and bladder cancer (RR = 1.10; 95% CI 1.05-1.16); in both instances, risks were higher among female residents. The highest excess risk for lung cancer was observed among residents in the Quartu-Parteolla health district (RR = 1.13; 95% CI 1.05-1.21), and it was slightly higher among male residents. The results appear to confirm the role of urban factors in increasing cancer risk.

Electroencephalography and visually evoked potentials during moderate hypoglycemia.

The effects of hypoglycemia per se on the electroencephalogram (EEG) and visually evoked potentials (VEPs) were studied in eight normal young adults. The EEG and VEPs were recorded before and during hypoglycemic clamp studies, carried out at plasma insulin and glucose concentrations of about 287 pmol/L and 2.38 mmol/L, respectively. From the mean power EEG spectra obtained during each testing condition, several parameters in each frequency band considered were compared statistically. During the eyes closed recording, the mean frequency of the alpha-band (8-13 Hz) decreased from 10.1 +/- 0.2 (+/- SE) Hz in both the right and left frontal leads during euglycemia to 8.8 +/- 0.2 and 8.8 +/- 0.1 Hz (left and right frontal leads, respectively; P less than 0.05) during hypoglycemia. In the same leads, the peak frequency decreased from 10.6 +/- 0.4 and 10.3 +/- 0.4 Hz to 9.6 +/- 0.4 and 9.5 +/- 0.3 Hz, respectively (P less than 0.05). A similar pattern of variation was found during the eyes open recording. In contrast, mean VEP latencies did not vary significantly; they were 118 +/- 3 ms (smallest image size; square wave signals subtending 30 min of arc) and 116 +/- 3 ms (largest image size; square wave signals subtending 60 min of arc) during euglycemia to 121 +/- 3 and 119 +/- 3 ms, respectively, during hypoglycemia. This study demonstrates that the earliest hypoglycemia-induced EEG alterations occur in the frontal regions and can be quantified in terms of decreased mean and peak frequencies of the alpha-band. VEP latency is less sensitive. If confirmed in diabetic patients, these data may provide a theoretical basis for developing a portable device to detect early hypoglycemia in those patients who lack warning symptoms.

Performance, ability to stay awake, and tendency to fall asleep during the night after a diurnal sleep with temazepam or placebo.

Sleep loss and increased sleepiness on the job are among the most prevalent problems encountered by people involved in night shift work, especially in cases of abrupt shift of the wake-sleep cycle. In such conditions, detrimental effects on performance are well documented. In these situations, to avoid decrements of performance at night, one possibility is to use hypnotics for improving the quality and quantity of daytime sleep. In this study, we evaluated the effects of 20 mg of temazepam on daytime sleep, the subsequent levels of nocturnal alertness/sleepiness, and performance in a laboratory simulation of acute night shift. For evaluating alertness, sleepiness, and performance we used, respectively, the maintenance of wakefulness test (MWT), the multiple sleep latency test (MSLT), and two pencil and paper tests: digit symbol substitution test (DSST) and deux barrages test (DBT). All tests were administered four times at 2-hour intervals during the nighttime after daytime sleep. Results showed that the ability to maintain wakefulness (MWT) and to perform some visuo-attentive tasks were substantially maintained during the night. On the other hand, sleep tendency (MSLT) linearly increased during the night. Temazepam resulted in being an effective diurnal hypnotic, increasing total sleep time with no residual detrimental effects on sleepiness and performance and with an increase in the ability to stay awake.

Rh system and intrauterine growth. Interaction with season of birth.

Based on the hypothesis that maternal-fetal genetic differences in membrane transport and signal transduction may influence intrauterine development, the recent acquisition on transport function of Rh protein prompted us to study the relationship between joint maternal-fetal Rh phenotype and birth weight. Considering that metabolic effect of maternal-fetal competition could be amplified by environmental conditions, we have investigated possible seasonal effects on such relationship. We have studied 5291 infants born in Sardinia in the period January 1993--December 1996 and 984 infants born in Rome during 1996. In Rh(-) mothers there is a significant association between season of birth and birth weight that shows the highest mean value in infants born in autumn (i.e. conceived in winter). The association is much more evident in male than in female infants. In male infants from Rh(-) mothers, the association between birth weight and season is significant in Rh(+) male newborns only. Recent observations by our group in NIDDM suggest that glucose transport in RBC may be related to D protein, thus we propose an interpretation of the present observation in terms of transport function. When the density of D protein in the infant is greater than in the mother, the balance is in favour of the infant who may attain a significant developmental advantage when conceived in the cold season.

Determinants of functional status in healthy Italian nonagenarians and centenarians: a comprehensive functional assessment by the instruments of geriatric practice.

OBJECTIVE: To evaluate the physical ability and psychocognitive status of a population more than 90 years of age with regard to sociodemographic, behavioral, and biomedical variables known to affect functional status in old age. DESIGN: A survey design was used. SETTING: Emilia Romagna, Northern Italy. PARTICIPANTS: Eighty-four healthy community-dwelling subjects aged 90 to 106 years. MEASUREMENTS: Sociodemographic variables, health behavior, anthropometric indices, and serum DHEAS levels were recorded. Functional assessment was performed by instruments currently used in geriatric practice: the Mini-Mental State Examination (MMSE), Geriatric Depression Scale (GDS), and Activities of Daily Living (ADL) scale. A stepwise multiple regression analysis was performed. RESULTS: GDS scores correlated directly with MMSE scores and inversely with ADL severity scores. Poor education, institutionalization, sensory impairment, muscular mass loss, and lower DHEAS levels were the variables with the highest correlation to functional impairment. Smoking, alcohol consumption, and marital status were relatively unimportant. An inverse association was found between DHEAS levels and dependency scores of single ADLs (continence, mobility). CONCLUSION: Impaired cognitive and physical ability with no increase in depression prevalence was found in a sample of subjects more than 90 years of age free of major age-related disease. Muscular mass and DHEAS levels seem to play a role in maintaining physical independence. In turn, physical independence, as well as social and cultural factors, strongly affect the compliance of long-lived subjects with psychocognitive tests currently used in the clinical evaluation of younger old people, suggesting that these instruments are not reliable for screening for cognitive impairment and depression in the oldest old subjects.

Effects of high altitude exposure on plasma and urinary digoxin-like immunoreactive substance.

Six young healthy subjects underwent a 20 day exposure to altitude, at 4930 m (16,174 ft), to evaluate possible plasma and urine digoxin-like immunoreactive substance (DLIS) changes accompanying the altered water and electrolyte balance induced by hypoxia. We studied DLIS, plasma renin activity (PRA), aldosterone, atrial natriuretic peptide (ANP), and arginine vasopressin (ADH) in serial blood and urine samples. An increase in DLIS in plasma (P less than .005) and urine (P less than .01) was found, while aldosterone was decreased (P less than .02). PRA, ADH, and ANP did not change significantly. A trend to a greater loss of sodium through urinary excretion, correlated with urinary DLIS values (r = 0.47, P less than .01), was observed. Data suggest a possible important role of DLIS in adaptive response of human organism to high altitude.

Assessing nighttime vigilance through a three-letter cancellation task (3-LCT): effects of daytime sleep with temazepam or placebo.

Nocturnal sleepiness is a common complaint suffered by night-shift workers, especially in conditions of an abrupt shift of the wake-sleep cycle. Alertness management strategies can minimize the adverse effects of sleep loss and circadian rhythm desynchronization and promote optimal vigilance in operational settings. Within these strategies. one possibility is to use short periods of "prophylactic sleep" (before long periods of work), which can be facilitated by hypnotics. Vigilance can be evaluated by means of several tests which, sometimes, imply procedures and devices not easily employable in operational settings. In such conditions pencil and paper tests of vigilance can be very useful in the assessment of attentional performance degradation due to sleep loss and/or inversion of the sleep-wake cycle. In this study we evaluated the sensitivity of a three-Letter Cancellation Task (3-LCT) in revealing nighttime variations of vigilance in a laboratory simulation of acute night shift, after a diurnal sleep with placebo (PLC) or temazepam (TMZ). Nocturnal levels of vigilance were also assessed using the Maintenance of Wakefulness Test (MWT) and the Multiple Sleep Latency Test (MSLT). All tests were administered four times at 2-h intervals during nighttime after a daytime sleep. Results show that the 3-LCT is sensitive to variations of vigilance occurring during a laboratory simulation of acute night shift. We also found some effects of TMZ, which in the first nocturnal session caused a slowing down of visuoattentive performance. Nocturnal variations of vigilance detected through the 3-LCT were similar to those revealed by means of MSLT, while the ability to maintain wakefulness was substantially spared during the night.

Smooth pursuit and saccadic eye movements as possible indicators of nighttime sleepiness.

Sleepiness is associated with specific variations of spontaneous oculomotor activity. During nocturnal sleep onset periods and also during the Multiple Sleep Latency Test (MSLT) a reduction of both rapid eye movements and blinks are recorded. In many operational contexts it might be even more relevant to assess whether and to what extent voluntary visual ocular control is affected by sleepiness due to sleep deprivation and time-of-day effects. In this study we evaluated, in a laboratory simulation of a sudden inversion of the sleep-wake cycle, the nocturnal modifications of smooth pursuit (SP) and saccadic (SAC) eye movements as possible indicators of sleepiness. Levels of sleepiness were objectively measured by means of MSLT and Maintenance of Wakefulness Test (MWT); subjective ratings of sleepiness were also obtained. After a diurnal sleep, five subjects underwent four nocturnal test sessions, each one comprising an SP and a SAC trial. Both the SP variables considered (velocity gain and phase) showed a trend similar to that one of MWT latencies, being significantly impaired only in the last nocturnal trial, when levels of sleepiness were maximal. Saccadic accuracy showed the same trend, being negatively affected by sleepiness only in the last nocturnal session. In addition, percentage of rejected (inappropriate) saccades showed a linear increase during the night, paralleling the shortening of sleep latency at MSLT and the linear increase of subjective ratings of sleepiness. These results, suggesting that saccadic performance, unlike SP, seems to be more sensitive to increasing levels of sleepiness, encourage further research on this topic.

Acutely shifting the sleep-wake cycle: nighttime sleepiness after diurnal administration of temazepam or placebo.

HYPOTHESIS: Sleepiness on the job is a common problem suffered by people involved in night shift work, especially in conditions of abrupt reversal of the sleep-wake cycle, such as emergencies and combat air operations. It is well known that sleepiness can severely affect alertness and performance. One of the most useful countermeasures is to take a prophylactic nap before working at irregular hours. To induce and maintain sleep in the "forbidden zones for sleep" during the day, it is possible to use suitable benzodiazepine hypnotics such as temazepam (TMZ). However, it is then necessary to monitor sleepiness and performance the night following the diurnal intake of the drug in order to evaluate possible side effects. METHODS: In this study, sleepiness was subjectively and objectively measured during the night after a daytime administration of TMZ 20 mg in soft gelatine capsules or placebo to obtain a prophylactic sleep. RESULTS AND DISCUSSION: Results showed the effectiveness of TMZ for inducing and maintaining diurnal sleep. This lengthening of total sleep time did not cause a decrease of sleepiness during the night, but no significant carry over effect of TMZ was present for nighttime sleep tendency. Both polygraphic and subjective measures of sleep latency decreased during the night. Finally, no significant relationship between the Stanford Sleepiness Scale and the Multiple Sleep Latency Test measures was found.

Burnout and health status in Italian air traffic controllers.

This study investigated burnout in air traffic controllers (ATC's). There were 109 Italian ATC's who filled out the Rome Burnout Inventory, a new tool for burnout assessment, during breaks in the working environment. The questionnaire assessed: 1) emotional-mental exhaustion (EME); 2) physical exhaustion (PE); 3) social support by components of the social network; 4) work- and nonwork-related stressors; 5) self-reported psychosomatic and psychiatric disorders. Our data show that the burnout syndrome is closely and positively related to age, years spent in air traffic control, professional dissatisfaction, and to work stressors, but not to nonwork stressors. In our sample, burnout was negatively correlated with social support provided by friends and family. The PE construct seemed to be unreliable in detecting physical burnout in Italian ATC's. Using analysis of variance, subjects with self-reported psychosomatic disorders did not show higher levels of EME scores. Further, EME was positively correlated with self-perceived psychological distress (anxiety, depression and impulse discontrol), but not with physician-rated psychopathology, as revealed by psychoactive drug intake. We suggest that burnout is a construct independent from clinical anxiety or depression.

Sleep and alertness during alternating monophasic and polyphasic rest-activity cycles.

People involved in shift work often have to face altered patterns of sleep and wakefulness. This is particularly true for schedules involving night shifts and/or fragmentation of duty periods throughout the 24-hr day. In such conditions, it can be difficult to obtain satisfactory periods of sleep, and sleepiness on duty is a frequent and dangerous occurrence. The aim of this study was to evaluate sleep and wakefulness periods of subjects whose work schedule was characterized by an alternation of 2 hours of activity and 4 hours of rest (sleep allowed), repeated 4 times throughout the 24-hr day. This schedule was alternated with 24 hours off duty. Nine healthy male volunteers were monitored by means of ambulatory polysomnography while attending their 24-hr rest-activity schedule. Sleep periods were visually scored according to standard criteria. Wake periods were visually scored using both 30 s and 5 s epochs in order to reveal episodes of drowsiness and/or microsleep. Results showed that total sleep time was substantially reduced as compared to the usual 7-8 hour monophasic nocturnal sleep. Subjects did not sleep during the first rest period (11.00-15.00). Time in sleep linearly increased in the course of the 3 remaining rest periods. Normal sleep stage distribution was substantially spared only in the last rest period (3.00-7.00 a.m.). With regard to duty periods, only a few microsleeps were detected and their number did not significantly vary across the four 2-hr activity periods. In conclusion, this rest-activity schedule, despite the considerable sleep reduction, allowed maintaining good levels of vigilance as shown by the virtual absence of EEG microsleeps. Whether future research will prove that this regimen does not cause an impairment of performance, it should be a suitable strategy for the management of continuous operations.

Sleepiness, alertness and performance during a laboratory simulation of an acute shift of the wake-sleep cycle.

Monitoring the presence of sleepiness on the job and its effects on performance is of primary importance for improving schedule systems of shiftworkers. Shiftworkers, often involved in night-time operations and irregular work schedules, frequently complain of nocturnal sleepiness especially in conditions of abrupt shift of the wake-sleep cycle. In this study, the authors evaluated the effects of a laboratory simulation of acute night-shift changes on sleepiness, vigilance and performance, using Maintenance of Wakefulness Test, Multiple Sleep Latency Test and three pencil and paper tests: Digit Symbol Substitution Test, 'Deux Barrages' Test and a 3-Letter Cancellation Task. All of the tests were administered four times at 2-hourly intervals during the night after daytime sleep. Results showed that the ability to maintain wakefulness and to perform simple visuo-attentive tasks is substantially spared during the night. On the other hand, sleep tendency and performance on a more complex and monotonous task (Letter Cancellation Task) reveal, respectively, increasing sleepiness and degrading performance.

Activation of the delta-globin gene by the beta-globin gene CACCC motif.

The promoter region of adult beta globin genes in humans and other mammals contains conserved regions of pivotal importance for their regulated tissue specific expression. These include the CACCC and CAAT motifs. The CACCC motif is duplicated in humans and other mammals. The human delta-globin gene lacks these conserved regions and its expression in normal individuals is about 3% that of the beta globin gene. Previous studies have shown that the introduction of the beta-globin CACCC or CAAT can activate the delta-globin gene promoter, but the effect of the distal CACCC element has not yet been tested. In the present study, using site-specific mutagenesis, we have introduced the consensus sequence for the distal and proximal CACCC motif and the CAAT box alone or in combination in the wild-type delta-globin gene promoter. The resulting mutants, as well as the wild type (wt) delta- and beta-globin gene promoters, have been analyzed in a transient expression assay in Cos7, K562, and MEL cell lines. The results show that the CACCC boxes can increase the transcription efficiency of the delta-globin gene promoter in both erythroid and non-erythroid cell systems. The contribution of the two CACCC elements is almost equal in the non-erythroid (Cos7) and erythroid embryonic-fetal cell lines (K562), while the proximal CACCC element is more active in adult erythroid cells (MEL). Nonetheless, duplication of this element does not appear to affect the efficiency of the promoter synergistically. Furthermore, to assess the competitive ability of the delta globin promoter containing the proximal or distal CACCC consensus sequences over the wt beta globin gene promoter, we have carried out transient expression experiments using DNA constructs in which the delta and beta globin gene promoters are linked in cis and are sharing a single enhancer (competitive transient expression). The results show that both CACCC elements are able to activate the delta globin gene promoter in Cos7 and K562 cells, although to a different extent, whereas only the proximal CACCC element is effective in increasing the transcription efficiency in MEL cells. These findings are in agreement with the more severe clinical phenotype produced by the beta-thalassemia mutations affecting the proximal CACCC box as compared with those within the distal CACCC box. The Erythroid Kruppel Like Factor (EKLF) is a nuclear protein restricted to erythroid cells which specifically bind the CACCC box sequence and activate the beta-globin gene. In the present study we carried out transactivation experiments of the mutagenized delta-globin gene promoter by introducing an EKLF expressing construct in erythroid cells. Constructs containing the proximal but not those bearing the distal CACCC element are transactivated. Our results indicate that the proximal CACCC box and, to a lesser extent, also the distal box have a role in the regulated stage specific expression of a beta-like globin gene, and show that the insertion of a single CACCC motif in the delta-globin gene promoter is sufficient to increase its activity. Nevertheless only the delta globin gene promoter containing the proximal CACCC element is able to compete with the wt beta globin gene promoter in the adult erythroid environment. These findings have potential relevance for the future prospective treatment of inherited hemoglobinopathies based on the conversion of the low functioning delta-globin gene into a high functioning beta-like globin gene.

Age differences in contingent negative variation activity of healthy young adults and presenile subjects.

20 selected right-handed very healthy subjects (10 young adults and 10 presenile subjects mean age 28.3 and 59.6) were tested for CNV activity with a simple warned reaction time (RT) paradigm. EEG and CNV components (post-S1, N1, P2, P3; early CNV; N1200; late CNV; CNV resolution) were recorded from Fz, C3, Cz, C4, P3, Pz, and P4 referenced to linked mastoid electrodes. EOG, RT and stimuli were also recorded. The presenile group differed significantly from the younger group in the auditory post-S1 N1 and P3, and in the early (O-wave) and late (P-wave) CNV complex components. A progressive amplitude reduction only in frontal leads between O-wave and P-wave with the lowest point being reached in the P-wave was characteristic in the presenile group. Further, presenile subjects showed relatively flat CNV waveshapes of low amplitude and, as a whole, performed a little less well than young persons. This finding suggests that the statistically significant changes in post-S1 EPRs and CNV activity recorded in our presenile subjects, without appreciable deficits in behavioral and mental performance, could be alerting signs of early brain involutional processes related to minimal and subclinical decrement of orienting, attentiveness and response preparation capabilities. If such is the case and it could be confirmed in a larger sample of very healthy subjects, these age-related changes in the presenium could be of considerable practical importance for clinical and research applications.

The human beta globin locus introduced by YAC transfer exhibits a specific and reproducible pattern of developmental regulation in transgenic mice.

The human beta globin locus spans an 80-kb chromosomal region encompassing both the five expressed globin genes and the cis-acting elements that direct their stage-specific expression during ontogeny. Sequences proximal to the genes and in the locus control region, 60 kb upstream of the adult beta globin gene, are required for developmental regulation. Transgenic studies have shown that altering the structural organization of the locus disrupts the normal pattern of globin gene regulation. Procedures for introducing yeast artificial chromosomes (YACs) containing large genetic loci now make it possible to define the sequences required for stage-restricted gene expression in constructs that preserve the integrity of the beta globin locus. We demonstrate that independent YAC transgenic lines exhibit remarkably similar patterns of globin gene expression during development. The switch from gamma to beta globin predominant expression occurs between day 11.5 and 12.5 of gestation, with no more than twofold differences in human beta globin mRNA levels between lines. Human beta globin mRNA levels were twofold to fourfold lower than that of mouse betamaj, revealing potentially significant differences in the regulatory sequences of the two loci. These findings provide an important basis for studying regulatory elements within the beta globin locus.

A beta-thalassaemia phenotype not linked to the beta-globin cluster in an Italian family.

This paper describes a family of Central Italian origin in which three patients in two generations had either thalassaemia intermedia or a late presenting form of thalassaemia major. Sequence analysis of the patients' DNA revealed that only one of the beta-globin genes was affected by a beta-thalassaemia mutation (the codon 39 nonsense mutation), the other being completely normal, apart from the complex rearrangement (-T +ATA) at position -530 5' to the CAP site of the beta-globin gene, which has uncertain clinical significance. Haematologically, all these patients were characterized by unusually low HbF levels (1.8-7.3%) for a beta-thalassaemia major or intermedia phenotype. The mother of the two patients with thalassaemia intermedia was heterozygous for beta-thalassaemia (codon 39 nonsense mutation), while the father had thalassaemia-like red cell indices, an increased alpha/non alpha chain synthesis ratio, a slight increase of HbF and a low HbA2 level, but showed entirely normal beta-globin gene sequences, apart from the complex rearrangement (-T +ATA) at position -530 5' to the CAP site. One of the thalassaemia intermedia patients married a normal woman and they had a child with thalassaemia major who inherited only the codon 39 nonsense mutation but not the complex rearrangement at position -530. The clinical phenotype of thalassaemia-intermedia or major in the patients from this family may be explained by postulating the inheritance of the double heterozygous state for beta-thalassaemia and for a mutation in a gene coding for an erythroid-specific DNA binding protein which may impair the function of the normal beta-globin gene. Heterozygosity for this postulated mutation (father of the patients with thalassaemia intermedia) may result in the production of a beta-thalassaemia carrier state with normal HbA2 level.

[Effects of acute and protracted hypoxia on plasma levels of atrial natriuretic factor]. / Effetti dell'ipossia acuta e protratta sui livelli plasmatici di fattore natriuretico atriale.

Acute hypoxia stimulates the release of atrial natriuretic factor (ANF) from isolated rat and rabbit hearts. Increased ANF plasma levels have been found in rats exposed to chronic hypoxia and recently some studies have been conducted on men, with discordant results. The aim of the present study was to verify changes in ANF plasma levels during acute and prolonged hypoxia in young healthy men. We studied 22 subjects (aged 20-28 years, mean 22.7 years) during a simulated exposure to altitude (5000 m) in a hypobaric chamber for 3 hours (A), and 6 subjects (aged 24-51 years, mean 36.5 years) during the scientific expedition to mount Poumori (Nepal 4930 m altitude) with an exposure at maximum altitude for 20 days (B). ANF was measured by the radioimmunoassay method. Results (pg/ml): (A) baseline: 29.4 +/- 18.6; 120 min: 32.0 +/- 17.4 (NS); 180 min: 35.4 +/- 17.1 (p less than 0.05). (B) baseline: 39.6 +/- 13.3; third day: 38.2 +/- 14.1; fifth day: 31.3 +/- 11; seventh day: 29.1 +/- 13.5; tenth day: 32.2 +/- 20.8; fifteenth day: 37.9 +/- 20.2; twentieth day: 34.6 +/- 23.7 (all differences were not significant). In (B) we observed a higher dispersion of values perhaps due to individual variability. The different behaviour of ANF plasma levels in acute and chronic conditions might be due to the adaptive modification of different physiological parameters as loss of plasma volume, natriuresis and attenuation of tissue hypoxia by enhanced erythropoiesis, observed more evidently during prolonged exposure.

A high frequency of the A30, B18, DR3, DRw52, DQw2 extended haplotype in Sardinian celiac disease patients: further evidence that disease susceptibility is conferred by DQ A1*0501, B1*0201.

This study characterizes by serological and molecular methods the HLA class I and class II alleles in a group of celiac disease children, their parents and a control group of Sardinian descent. We found the DR3-DQw2 haplotype in all patients which was, in almost all cases (84%), associated with the HLA-A30, B18, DR3, DRw52, DQw2 extended haplotype named "Sardinian haplotype" because of its frequency (12-15%) in this Caucasian population. This is the first time that this DQw2-linked haplotype has been reported with such a high frequency in CD. However, no different distribution of "Sardinian haplotype" was found comparing CD patients with 91 haplotyped DQw2-positive controls. This finding indicates that the DQw2 antigen in Sardinians is almost always associated with the A30, B18, DR3, DRw52, DQw2 extended haplotype. The DQA1 and DQB1 second exon sequence analysis of the B18,DR3 and B8,DR3 haplotypes showed the DQA1*0501 and DQB1*0201 alleles which shared the already published sequences. DPB1 subtyping showed the DPB1*0301 allele more frequently (p less than 0.005) in CD patients but this difference was no longer significant when patients and controls, both heterozygous for the DR3-DQw2 haplotype, were compared. We suggest that the divergent HLA extended haplotypes and DP allele associated with CD, described in different Caucasian populations, can be explained by the particular DQw2 linkage disequilibrium in each population.

The HLA DQB1*0502 allele is neutrally associated with insulin-dependent diabetes mellitus in the Sardinian population.

In the Sardinian population a very high incidence of insulin-dependent diabetes mellitus (IDDM) and the lack of HLA-DR2 protective effect due to the high frequency of the A2, Cw7, B17, 3F31, DR2, DQw1 extended haplotype has been reported. This haplotype, carrying a Serine at position 57 of the DQB1*0502 allele, has been previously reported to be underrepresented in patients when compared to controls. In order to provide an explanation for this finding, we defined by RFLP analysis the HLA haplotype of 45 Sardinian IDDM patients and 49 controls. All DR-2DQw1 subjects were molecularly characterized at the HLA DQA and DQB loci. All DR2-positive patients and the vast majority of the DR2-positive controls had the DQB1*0502 allele at the DR2-linked DQB1 locus, with no statistically significant difference between the two groups. All DQA1 genes were the ones expected, with only two exceptions. Nine out of 10 of the DR2-positive patients were compound heterozygotes for DQB1*0201/DQB1*0502 alleles; only this allele combination was significantly increased (p less than 0.0003). Our data suggests that a) the DQB1*0502 allele is neutral for IDDM development and b) the susceptibility to IDDM in our DR2-positive patients is related to the compound heterozygous state between the neutral DQA1*0102/DQB1*0502 and the susceptibility DQA1*0501/DQB1*0201 alleles.