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Germline BRCA (gBRCA) mutations predispose to an increased risk of breast and ovarian cancer among other neoplasms. Recently, several genomic alterations such as ALK and ROS-1 rearrangements have been described as molecular drivers of venous thromboembolism (VTE). The association of gBRCA mutations and VTE is unknown. We performed an observational, retrospective, single-center study to determine the VTE incidence in consecutive patients with gBRCA mutations and cancer diagnosis attended in the multidisciplinary heredofamiliar cancer unit (HFCU) of Hospital General Universitario Gregorio Maranon, Spain, from 2010 to 2019. One-hundred and forty-one patients were included in the analysis. The overall VTE incidence was 12.8%. The highest incidence was reported in ovarian cancer patients (20.0%), followed by patients with both ovarian and breast cancers (16.6%) and the lowest was found in breast cancer (4.9%). No difference in the type of gBRCA mutation (1 or 2) in terms of VTE rate was observed. Sixty one percent of the patients were receiving anti-cancer therapy at the time of VTE diagnosis and the majority of the events (83.3%) were diagnosed in ambulatory setting. Khorana score was of limited value to detect high-risk patients. The VTE incidence observed in our study is consistent with prior data described in general population of breast and ovarian cancer. The risk of VTE in these patients seems to be driven by the type of cancer. We have not observed any significant interaction of gBRCA mutation status and cancer-associated thrombosis.

OBJECTIVE: To describe the clinical, biochemical, and genetic features of both new and previously reported patients with congenital disorders of glycosylation (CDGs) diagnosed in Portugal over the last 20 years. STUDY DESIGN: The cohort includes patients with an unexplained multisystem or single organ involvement, with or without psychomotor disability. Serum sialotransferrin isoforms and, whenever necessary, apolipoprotein CIII isoforms and glycan structures were analyzed. Additional studies included measurement of phosphomannomutase (PMM) activity and analysis of lipid-linked oligosaccharides in fibroblasts. Sanger sequencing and massive parallel sequencing were used to identify causal variants or the affected gene, respectively. RESULTS: Sixty-three individuals were diagnosed covering 14 distinct CDGs; 43 patients diagnosed postnatally revealed a type 1, 14 a type 2, and 2 a normal pattern on serum transferrin isoelectrofocusing. The latter patients were identified by whole exome sequencing. Nine of them presented also a hypoglycosylation pattern on apolipoprotein CIII isoelectrofocusing, pointing to an associated O-glycosylation defect. Most of the patients (62%) are PMM2-CDG and the remaining carry pathogenic variants in ALG1, ATP6AP1, ATP6AP2, ATP6V0A2, CCDC115, COG1, COG4, DPAGT1, MAN1B1, SLC35A2, SRD5A3, RFT1, or PGM1. CONCLUSIONS: Portuguese patients with CDGs are presented in this report, some of them showing unique clinical phenotypes. Among the 14 genes mutated in Portuguese individuals, 8 are shared with a previously reported Spanish cohort. However, regarding the mutational spectrum of PMM2-CDG, the most frequent CDG, a striking similarity between the 2 populations was found, as only 1 mutated allele found in the Portuguese group has not been reported in Spain. ispartof: JOURNAL OF PEDIATRICS vol:231 pages:148-156 ispartof: location:United States status: published

In a patient with Usher syndrome and atypical muscle complaints, we have identified two separate variants in MYO7A andNEB genes by exome sequencing. The homozygous variants in these two recessive genes could explain the full phenotype of our patient., In a patient with Usher syndrome and atypical muscle complaints, we have identified two separate variants in MYO7A and NEB genes by exome sequencing. The homozygous variants in these two recessive genes could explain the full phenotype of our patient.

Rationale: Obstructive sleep apnea (OSA) is associated with poor blood pressure (BP) control and resistant hypertension (RH). Nevertheless, studies assessing its prevalence, characteristics, and association with BP control in patients with RH are limited. Objectives: The aim of this multicenter study was to assess the prevalence of OSA in a large cohort of subjects with RH and to evaluate the association of OSA with BP control. Methods: We recruited consecutive subjects with RH from three countries. A formal sleep test and blood pressure measurements, including 24-hour ambulatory blood pressure monitoring, were performed in all participants. Results: In total, 284 subjects with RH were included in the final analysis. Of these, 83.5% (95% confidence interval [CI], 78.7-87.3%) had OSA (apnea-hypopnea index >= 5 events/h); 31.7% (95% CI 26.5-37.3%) had mild OSA, 25.7% (95% CI, 21-31.1%) had moderate OSA, and 26.1% (95% CI, 21.3-31.5%) had severe OSA. Patients with severe OSA had higher BP values than subjects with mild to moderate or no OSA. A greater effect was observed on the average nighttime BP, with an adjusted effect of 5.72 mm Hg (95% CI, 1.08-10.35 mm Hg) in severe OSA compared with participants without OSA. A dose-response association between the severity of OSA and BP values was observed. The prevalence of severe OSA was slightly higher in uncontrolled participants (adjusted odds ratio, 1.69; 95% CI, 0.97-2.99) but was not statistically significant. Conclusions: The present study confirms the high prevalence of OSA in participants with RH. Furthermore, it shows a dose-response association between OSA severity and BP measurements, especially in the nighttime.

Intellectual disability affects 2% - 3% of the general population, with a chromosomal abnormality being found in 4% - 28% of these patients and a cryptic subtelomeric abnormality in 3% - 16%. In most cases, these subtelomeric rearrangements are submicroscopic, requiring techniques other than conventional karyotype for detection. They may be de novo or inherited from an affected parent or from a healthy carrier of a balanced chromosomal abnormality. The aim of this study was to characterize patients from our medical genetics center, in whom both a deletion and duplication in subtelomeric regions were found.Clinical and cytogenetic characterization of 21 probands followed at our center, from 1998 until 2017, with subtelomeric rearrangements.There were 21 probands from 19 families presenting with intellectual disability and facial dysmorphisms. Seven had behavior changes, five had epilepsy and 14 presented with some other sign or symptom. Four had chromosomal abnormalities detected by conventional karyotype and four were diagnosed by array-comparative genomic hybridization. In four cases, parental studies were not possible. The online mendelian inheritance in man classification was provided whenever any of the phenotypes (deletion or duplication syndrome) was dominant.Patients and relevant family members were clinically and cytogenetically characterized. Although rare, subtelomeric changes are a substantial cause of syndromic intellectual disability with important familial repercussions. It is essential to remember that a normal array-comparative genomic hybridization result does not exclude a balanced rearrangement in the parents.Parental genetic studies are essential not only for a complete characterization of the rearrangement, but also for accurate genetic counselling and screening of family members at risk for recurrence.Introdução: O défice intelectual afeta 2% – 3% da população geral, sendo encontrada uma alteração cromossómica em 4% – 28% dos casos e uma alteração subtelomérica em 3% – 16%. Estas alterações subteloméricas são, na maioria dos casos, submicroscópi- cas, não sendo detetadas no cariótipo convencional. Podem ser de novo ou herdadas de um progenitor afetado ou de um progenitor saudável portador de um rearranjo equilibrado. O objetivo deste estudo foi caracterizar os doentes seguidos no nosso centro de gené- tica médica com uma deleção e uma duplicação nas regiões subteloméricas. Material e Métodos: Caracterização clínica e citogenética de 21 probandos com alterações subteloméricas seguidos no nosso centro entre 1998 e 2017. Resultados: Foram caracterizados 21 probandos que apresentavam défice intelectual e dismorfia facial, pertencentes a 19 famílias. Sete tinham alterações do comportamento, cinco epilepsia e 14 outro sinal ou sintoma. Quatro tinham alterações no cariótipo e quatro foram diagnosticados por array-comparative genomic hybridization. Em quatro famílias não foi possível o estudo dos progenitores. Quando um dos fenótipos era dominante (síndrome de deleção ou duplicação), foi atribuída a classificação online mendelian inheri- tance in man. Discussão: Foi realizada classificação dos doentes e das famílias. As alterações nas regiões subteloméricas são, apesar de raras, uma causa substancial para défice intelectual sindrómico com repercussões familiares importantes. É essencial lembrar que um array- comparative genomic hybridization normal não exclui um rearranjo equilibrado familiar. Conclusão: O estudo dos progenitores é essencial não só para caracterização completa do rearranjo mas também para um aconse- lhamento genético preciso e identificação de familiares em risco de recorrência.

Introduction: Patients with resistant hypertension (RH) have a high risk of developing cardiovascular events; therefore, new therapeutic approaches to better control blood pressure may be useful in improving cardiovascular outcomes. The prevalence of obstructive sleep apnea (OSA) is very high among patients with RH. Continuous positive airway pressure (CPAP) has been shown to be an effective treatment for reducing blood pressure in patients with RH. Nevertheless, the long-term effect of CPAP treatment on cardiovascular outcomes has not been explored. The main objective of the SARAH study is to assess the impact of OSA and its treatment on cardiovascular outcomes (morbidity and mortality) in patients with RH. Methods: This study is a multi-center, prospective, observational cohort study. A total of 1371 patients with RH will be enrolled in the study and followed once a year for five years. At inclusion, ambulatory blood pressure monitoring (ABPM) and a sleep study will be performed in all subjects. Socio-demographic, clinical and cardiovascular variables will be collected at baseline and follow-up. Subsequently, subjects with OSA will be managed according to local standard practice. Based on the OSA diagnosis and its treatment, three cohorts of subjects with RH will be defined: non-OSA, treated OSA and non-treated OSA. Conclusions: This study will contribute to elucidating the long-term impact of OSA treatments on blood pressure control and cardiovascular outcomes in patients with RH. These results will contribute to improve the cardiovascular prognosis of patients with RH. (C) 2018 SEPAR. Published by Elsevier Espana, S.L.U. All rights reserved.

Co-occurrence of hyperinsulinaemic hypoglycaemia and polycystic kidney disease (HIPKD) has been recently described. It is caused by a non-coding variant in the promoter region for phosphomannomutase 2 (PMM2), c.-167G>T, both in homozygous or compound heterozygous variants with deleterious coding. Although PMM2 has been associated with congenital disorder of glycosylation, patients do not present with this phenotype and have normal carbohydrate-deficient transferring testing. The authors present a rare case where specific PMM2 study was performed as a result of clinical suspicions. The patient was a 6-year-old female followed at our clinic due to congenital hyperinsulinism since she was 1 month old. She also presented with bilateral polycystic kidneys, detected in prenatal set, and simple hepatic cysts, for which she was treated with diazoxide and captopril. Initial metabolic and genetic studies were normal. PMM2 gene sequence study revealed the promotor variant c.-167G>T in compound heterozygosity with the previously described pathogenic variant c.422G>A (p.Arg141His), confirming the diagnosis of HIPKD. This is a notable case as it highlights the importance of keeping this diagnostic hypothesis in mind and serves as a reminder to perform proper clinical and genetic investigation. A correct, and early, diagnosis will avoid unnecessary additional investigations and will allow appropriate genetic counselling for this autosomal recessive disorder. info:eu-repo/semantics/publishedVersion

Introduction: The peak oxygen uptake (VO2) obtained in CPET is a good predictor of postoperative morbimortality in LCS. However some preoperative risk assessment algorithms include “low-technology exercise tests” as the ISWT. We compared the algorithms proposed in the guidelines ACCP 2013* which includes ISWT performance and those of the ERS/ESTS 2009**. Methods: Patients who were candidates for pulmonary resection from September 2017 to November 2018 were included. Spirometry, lung volumes, DLCO and arterial blood gase were performed. Patients with FEV1% or DLCO Preoperative risk was calculated according to both guidelines and the concordance between them was analyzed. Results: 41 patients were included (28 men); mean age 65, mean FEV1 62% and DLCO 54%. The mean peak VO2 was 17.1 +/-4.5ml/kg/min (75+/-25% RV) Fifty-one% of patients achieved >400m in the ISWT (mean shuttle walk distance 392 +/-97 m). There was a significant correlation between shuttle walk distance and peak VO2 (r=0.64, p For the assessment of “high risk” both algorithms matched in 100%. Twelve patients (29%) were classified as “low risk” according to the ACCP and as “moderate risk” by the ERS/ESTS. Conclusions: Including ISWT performance in the ACCP* algorithm allows it to classify “high risk patients” in the same way as ERS / ESTS**. However, ACCP overestimates the ”up to pneumonectomy" surgery recommendation in those patients whose CPET would have not have allowed it according to the ERS/ESTS.

Introduction: Despite advances in surgical techniques and anaesthetic management in lung cancer surgery, cardiopulmonary complications are the most important causes of postoperative morbimortality. The aim of this study was to evaluate Cardiopulmonary Exercise Test (CPET) parameters as predictors of postoperative complications in lung cancer surgery patients. Method: This observational prospective study included patients who were candidates for lung cancer surgery (LCS) at our hospital. Patients with either a post-bronchodilator FEV1% or DLCO Results: 118 patients were included, (71% men); mean age was: 66 + 10 years; mean FEV1 (%): 69 ± 14 and mean DLCO (%) = 68 ± 16. The mean VO2 max (ml/kg/min) was 18 ± 4. The incidence of complications was 16% (84.8% of total complications were respiratory). Table 1 shows the clinical, functional and CPET characteristics of patients according to the presence of complications. After adjusting for perioperative factors by logistic regression, the best predictor factors of postoperatorive total complications were exercise VE/VCO2 slope and VE max (OR: 1,12, p=0,018; OR: 0,95; p=0,019, respectively). For postoperative respiratory complications, the best predictor factors were VO2 max and FEV1/FVC (OR=0.751, p=0.003; OR=0.932, p=0.006, respectively) Conclusions: The predictive capacity of VO2 max and VE/VCO2 for postoperative morbidity supports the use of CPET as a tool to improve the stratification of risks in lung cancer patients. These results reaffirm the inclusion of the CPET in the first steps of preoperative risk assessment algorithms.

This report is on two novel patients with RFT1-CDG. Their phenotype is characterized by mild psychomotor disability, behavioral problems, ataxia, and mild dysmorphism. Neither of them shows signs of epilepsy, which was observed in all RFT1-CDG patients reported to date (n = 14). Also, deafness, which is often associated with this condition, was not observed in our patients. Molecular analysis of RFT1 showed biallelic missense variants including three novel ones: c.827G > A (p.G276D), c.73C > T (p.R25W), and c.208T > C (p.C70R).

Introduction: The maximal oxygen consumption obtained in a cardiopulmonary exercise test (CPET) is a good predictor of the risk in lung cancer surgery. Clinical practice guidelines differ with regard to the indication of CPET. The aim of this study was to compare the algorithms proposed in the guidelines of the European Respiratory Society (ERS/ESTS)* and the American College of Chest Physicians (ACCP)**. Methods: This observational prospective study included patients who were candidates for lung cancer surgery (LCS) at our hospital. Patients with either a post bronchodilator FEV1% or diffusing capacity of carbon monoxide (DLCO) Results: A total of 125 CPET were performed. The overall diagnostic concordance between algorithms was 72% (Kappa index= 0.31; p= 0.000). For the assessment of “low risk” (surgery until pneumonectomy) the algorithms coincided in 64.8% of cases. 18.4% of patients were classified as “low risk” according to the ACCP and as “moderate risk” by the ERS/ESTS (surgery until lobectomy). According to the ACCP, 15 patients were classified as “high-risk” (proposed surgery not recommended/atypical or minor surgery). According to the ERS/ESTS, five of these 15 patients were classified as “moderate risk” and seven as “low risk”. Conclusions: The ERS/ESTS algorithm is more conservative for patients who are candidates for major lung resection. It allows LVRS in patients with pulmonary function alteration who would have been rejected according to the ACCP. * Eur Respir J 2009; 34: 17-41 ** Chest 2007; 132; 161S-177S

Infantile Refsum disease (IRD) is one of the less severe of Zellweger spectrum disorders (ZSDs), a group of peroxisomal biogenesis disorders resulting from a generalized peroxisomal function impairment. Increased plasma levels of very long chain fatty acids (VLCFA) and phytanic acid are biomarkers used in IRD diagnosis. Furthermore, an increased plasma level of phytanic acid is known to be associated with neurologic damage. Treatment of IRD is symptomatic and multidisciplinary.The authors report a 3-year-old child, born from consanguineous parents, who presented with developmental delay, retinitis pigmentosa, sensorineural deafness and craniofacial dysmorphisms. While the relative level of plasma C26:0 was slightly increased, other VLCFA were normal. Thus, a detailed characterization of the phenotype was essential to point to a ZSD. Repeatedly increased levels of plasma VLCFA, along with phytanic acid and pristanic acid, deficient dihydroxyacetone phosphate acyltransferase activity in fibroblasts and identification of the homozygous pathogenic mutation c.2528G>A (p.Gly843Asp) in the PEX1 gene, confirmed this diagnosis. Nutritional advice and follow-up was proposed aiming phytanic acid dietary intake reduction. During dietary treatment, plasma levels of phytanic acid decreased to normal, and the patient's development evaluation showed slow progressive acquisition of new competences.This case report highlights the relevance of considering a ZSD in any child with developmental delay who manifests hearing and visual impairment and of performing a systematic biochemical investigation, when plasma VLCFA are mildly increased. During dietary intervention, a biochemical improvement was observed, and the long-term clinical effect of this approach needs to be evaluated. info:eu-repo/semantics/publishedVersion

The Aristaless-related homeobox (ARX) gene is implicated in intellectual disability with the most frequent pathogenic mutations leading to expansions of the first two polyalanine tracts. Here, we describe analysis of the ARX gene outlining the approaches in the Australian and Portuguese setting, using an integrated clinical and molecular strategy. We report variants in the ARX gene detected in 19 patients belonging to 17 families. Seven pathogenic variants, being expansion mutations in both polyalanine tract 1 and tract 2, were identifyed, including a novel mutation in polyalanine tract 1 that expands the first tract to 20 alanines. This precise number of alanines is sufficient to cause pathogenicity when expanded in polyalanine tract 2. Five cases presented a probably non-pathogenic variant, including the novel HGVS: c.441_455del, classified as unlikely disease causing, consistent with reports that suggest that in frame deletions in polyalanine stretches of ARX rarely cause intellectual disability. In addition, we identified five cases with a variant of unclear pathogenic significance. Owing to the inconsistent ARX variants description, publications were reviewed and ARX variant classifications were standardized and detailed unambiguously according to recommendations of the Human Genome Variation Society. In the absence of a pathognomonic clinical feature, we propose that molecular analysis of the ARX gene should be included in routine diagnostic practice in individuals with either nonsyndromic or syndromic intellectual disability. A definitive diagnosis of ARX-related disorders is crucial for an adequate clinical follow-up and accurate genetic counseling of at-risk family members. Unit for Multidisciplinary Research in Biomedicine, UMIB, ICBAS-UP, Porto, Portugal was funded by FEDER funds of the Operational Program for Competitiveness Factors – COMPETE through FCT – Foundation for Science and Technology under the project: Fcomp-01-0124-FEDER-015896. The Neurogenetics research program in the Department of Paediatrics, University of Adelaide, Australia was funded by the Australian National Health and Medical Research Council (Grant No. 1063025). C. S. is supported Australian Research Council (Future Fellowship FT120100086)

This report describes the trends of chorionic villus sampling (CVS) referred for prenatal genetic diagnosis in the past two and a half decades in a Portuguese Center. Our cohort of 491 CVS was mostly performed by the transcervical method at the 12th gestational week. Data collected within the framework of this study relate to the following: sampling method, referral reason versus abnormality and incidence of procedure-related pregnancy loss, that declined to about 0.5% over the last 15 years. The year 2000 represented a change in referral reasons for chorionic tissue collection, shifting from almost exclusively for cytogenetic testing to an increasing number of molecular tests for monogenic disorders. Herein, success rates as well as cytogenetic and/or molecular DNA results are presented. These latter include not only tests for several monogenic disorders, but also aneuploidy and maternal cell contamination screening. This retrospective analysis reiterates that CVS is a safe and reliable first trimester technique for prenatal diagnosis in high genetic risk pregnancies.

MJD is the most frequent dominant ataxia and an incapacitating disorder. Onset is most frequently during the reproductive years, and genetic counselling is its only means of prevention. The causative mutation—an expansion of a (CAG)n on chromosome 14q32.1—can now be directly detected. We now report the first two cases of prenatal diagnosis (PND). The first presented as a simultaneous request for predictive testing and PND at 14 weeks of pregnancy. Owing to time constraints, we performed a full protocol of counselling with shorter intervals between sessions, while psycho-social evaluation of the other parent and obstetric consults were also begun. We ensured that the couple wished termination if the fetus was a carrier, to avoid a presymptomatic test for the unborn child. We were thus able to deliver test results two weeks before PND. As the fetus carried an expanded allele (77 CAGs) inherited from his father, termination was performed and the couple received counselling, psychological and social support. The second case was the fetus of a carrier-mother that was diagnosed as non-carrier, also after amniocentesis. © 1998 John Wiley & Sons, Ltd.

There is compelling evidence that obstructive sleep apnoea (OSA) can affect metabolic syndrome (MetS) and cardiovascular risk, but the intermediate mechanisms through which it occurs have not been well defined. We explored the impact of OSA in morbidly obese patients with MetS on adipokines, pro-inflammatory markers, endothelial dysfunction, and atherosclerosis markers.We included 52 morbidly obese patients in an observational study matched for age, gender and central obesity in 3 groups (OSA-MetS, Non-OSA-MetS, and Non OSA-non-MetS). Anthropometrical, blood pressure, and fasting blood measurements were obtained the morning after an overnight polysomnography. VEGF, soluble CD40 ligand (sCD40L), TNF-α, IL-6, leptin, adiponectin, and chemerin were determined in serum by ELISA. OSA was defined as apnea/ hypopnea index ≥ 15 and MetS by NCEP-ATP III.Cases and control subjects did not differ in age, BMI, waist circumference, and gender (43 ± 10 years, 46 ± 5 kg/m(2), 128 ± 10 cm, 71% females). The cases had severe OSA with 47 (32-66) events/h, time spent90% SpO2 7% (5%-31%). All groups presented similar serum cytokines, adipokines, VEGF, and sCD40L levels.In a morbidly obese population with established MetS, the presence of OSA did not determine any differences in the studied mediators when matched by central obesity. Morbidly obese NonOSA-NonMetS had a similar inflammatory, adipokine VEGF, and sCD40L profile as those with established MetS, with or without OSA. Obesity itself could overwhelm the effect of sleep apnea and MetS in the studied biomarkers.Salord N; Gasa M; Mayos M; Fortuna-Gutierrez AM; Montserrat JM; Sánchez-de-la-Torre M; Barceló A; Barbé F; Vilarrasa N; Monasterio C. Impact of OSA on biological markers in morbid obesity and metabolic syndrome.

Maria Luis Cardoso1,2, Mafalda Barbosa3,4, Ana Maria Fortuna3 and Franklim Marques1,2 1Faculty of Pharmacy, University of Porto, Porto 2Institute for Molecular and Cell Biology, University of Porto, Porto 3Medical Genetics Centre Jacinto Magalhaes, National Health Institute Ricardo Jorge Porto 4Life and Health Sciences Research Institute, School of Health Sciences, University of Minho, Braga Portugal

Focal dermal hypoplasia (FDH, Goltz syndrome), is an X-linked dominant mesoectodermal developmental disorder, involving skin, skeleton, eyes, teeth, and other organs. Mutations in PORCN, which stimulates the secretion of wingless family signal proteins, are found in FDH patients. A female fetus presented at 34 weeks gestation with interuterine growth restriction (IUGR), asymmetry, limb anomalies, microphthalmia, and lung anomaly. Focal dermal hypoplasia was confirmed at birth, with hypoplastic areas of skin, malformation of the limbs, diaphragmatic hernia, and ocular anomalies. Mutation analysis of PORCN revealed a nonsense mutation—Y359X. She presented natal teeth, an unexpected feature considering the role of the Wnt pathway in tooth development.

Susana Carvalho1*, Marcia Martins2, Ana Fortuna3, Umbelina Ramos4, Carlos Ramos5 and Maria Ceu Rodrigues5 1Centro Hospitalar do Porto-Unidade Maternidade Julio Dinis, Porto, Portugal 2Centro Hospitalar do Porto-Unidade Maternidade Julio Dinis, Pediatrics, Porto, Portugal 3Instituto de Genetica Medica Jacinto Magalhaes, Genetics, Porto, Portugal 4Centro Hospitalar do Porto, Porto, Portugal 5Centro Hospitalar do Porto-Unidade Maternidade Julio Dinis, Porto, Portugal

Blood Cells Mol Dis. 1999 Apr;25(2):130-8. T cell numbers relate to bone involvement in Gaucher disease. Lacerda L, Arosa FA, Lacerda R, Cabeda J, Porto G, Amaral O, Fortuna A, Pinto R, Oliveira P, McLaren CE, Sá Miranda C, de Sousa M. Department of Genetics Neurobiology, Porto University, Portugal. Abstract The major elements of bone pathology in Gaucher disease are a failure of osteoclast and osteoblast function, resulting in osteopenia and also osteonecrosis. T lymphocytes have recently been found to be involved in the regulation of osteoblast/osteoclast activity in vitro. In the present report the peripheral blood T major lymphocyte subsets were investigated in a group of genotyped type 1 Gaucher disease patients. A total of 31 patients were studied: 21 non-splenectomized (5 N370S homozygotes) and 10 splenectomized (of whom 1 was a N370S homozygote). The results show that non-splenectomized patients present a decrease in absolute numbers of peripheral blood T lymphocytes, specially the CD4+ T subset. However, when patients were analyzed with respect to the presence of bone disease, the number of CD8+ T lymphocytes was found to be statistically significantly lower in patients presenting bone involvement. Furthermore, lower numbers of CD8+ T lymphocytes were significantly correlated with higher levels of plasma tartrate resistant acid phosphatase (TRAP) activity, a putative marker of osteoclast cell activity. These in vivo findings are in agreement with the results reached in vitro by others. They provide an additional marker of disease severity in Gaucher disease. In the group of genotyped Gaucher disease patients, the majority of the N370S homozygous patients presented a clinically milder phenotype, including the absence of bone involvement, confirming earlier reports predicting that a number of these patients may remain undiagnosed. Collectively the homozygosity for the N370S mutation and normal T cell numbers may provide additional markers for the clinical heterogeneity of Gaucher disease. PMID: 10389595 [PubMed - indexed for MEDLINE