Role of Vitamin D in Hospitalized Children With Lower Tract Acute Respiratory Infections.

BACKGROUND: Vitamin D is known to have modulatory actions in the immune system. Its influence on the severity of lower tract acute respiratory infections (LT-ARIs) is unclear. OBJECTIVES: The aim of the present study was to evaluate the role of vitamin D on LT-ARI in paediatric patients. METHODS: Children admitted to hospital with LT-ARI were prospectively recruited through the GENDRES network (March 2009-May 2013). The 25-hydroxyvitamin D (25-OHD) levels were measured by immunoassay. The severity of the illness was evaluated according to clinical scales, length of hospital stay, ventilatory requirements, and pediatric intensive care unit admission. RESULTS: A total of 347 patients with a median (interquartile range) age of 8.4 (2.6-21.1) months were included. The mean (SD) 25-OHD levels in our series were 27.1 (11.3) ng/mL. In this study, a cutoff value of ≥30 ng/mL was considered optimal vitamin status. Patients with 25-OHD levels <20 ng/mL were at a higher risk of showing severe signs of respiratory difficulties (OR 5.065, 95% confidence interval 1.998-12.842; P = 0.001) than patients with normal values, and had a 117% higher risk of oxygen necessity and 217% higher risk of ventilatory requirement than those patients with normal values. An inverse correlation was found between 25-OHD levels and the severity in the evaluated scales. 25-OHD levels did not influence PICU admission rate or length of hospital stay. CONCLUSIONS: 25-OHD levels of children admitted because of a LT-ARI are <30 ng/mL. Lower levels of 25-OHD were found to be correlated with severity of the disease. The possible role of abnormal 25-OHD levels as a facilitator or consequence of the infection needs further evaluation.

NEmecum: digital tool for assisting in the prescription and dispensing of enteral nutrition formulas and infant preparations / NEmecum: herramienta digital de ayuda a la prescripción y dispensación de fórmulas de nutrición enteral y preparados infantiles.

Introduction: Introduction: there is a wide variety of enteral nutrition and infant formulas preparations. When there is a need to find infomation on a product, only the infomation from industy is available. Comparison amomg products becomes then ardous. Objective: to describe the development of NEmecum as the first website that allows a directed and independent search for enteral nutrition products and infant formulas, currently available in Spain, and to evaluate the initial use of NEmecum. Methods: the structure of a database that unifies the parameters of all formulas was developed, and the nutritional composition of all formulas was analyzed. Subsequently, the main search algorithms were selected and the digital tool was codified. Intensive dissemination was performed and the impact was evaluated. The profile of users and registered centers and the use of the tool were analyzed, and its usability was evaluated using the System Usability Scale (SUS) questionnaire. Results: a free-access responsive website (http://nemecum.com) that allows searches based on pre-established search filters was obtained. This tool allows for a detailed analysis avalaible formulas in Spain by observing a wide variety of formulas with similar characteristics. The dissemination campaign managed to increase its use exponentially, currently reaching 1,370 users and 79 registered centers. Usability was rated as excellent. Conclusion: the development of the NEmecum represents a valuable tool in the search and consultation of the characteristics of enteral nutrition formulas and infant preparations.

Introducción: Introducción: existe una amplia variedad de fórmulas o preparados de nutrición enteral y fórmulas o preparados infantiles. La consulta de información relacionada debe hacerse en las herramientas propias de cada laboratorio, lo que dificulta la visión crítica y la comparativa entre las mismas. Objetivo: describir el desarrollo de NEmecum como la primera web que permite realizar una búsqueda dirigida e independiente de fórmulas de nutrición o preparados infantiles, analizar el abanico nutricional actual en España y evaluar los datos de uso de la herramienta. Métodos: se desarrolló la estructura de una base de datos que unifica los parámetros de todas las fórmulas y se analizó el abanico nutricional español. Posteriormente, se seleccionaron los principales algoritmos de búsqueda dirigida y se codificó la herramienta digital. Se llevó a cabo una intensa difusión y se evaluó el impacto obtenido. Se analizaron el perfil de usuarios y centros registrados y los datos de uso de la herramienta y se evaluó su usabilidad mediante el cuestionario System Usability Scale (SUS). Resultados: se obtuvo una web responsive de acceso gratuito (http://nemecum.com) que permite realizar búsquedas dirigidas en base a unos filtros de búsqueda preestablecidos. La herramienta permitió analizar detalladamente el abanico nutricional en España, observándose la gran variedad de fórmulas disponibles de similares características. La campaña de difusión consiguió incrementar su uso de forma exponencial y cuenta actualmente con 1.370 usuarios y 79 centros registrados. La usabilidad fue valorada como excelente. Conclusión: el desarrollo de NEmecum supone una herramienta valiosa en la búsqueda y consulta de datos de fórmulas o preparados de nutrición enteral y fórmulas o preparados infantiles.

Benefits of Paediatric to Adult Transition Programme in Inflammatory Bowel Disease: The BUTTERFLY Study of GETECCU and SEGHNP.

(1) Background: Transition is a planned movement of paediatric patients to adult healthcare systems, and its implementation is not yet established in all inflammatory bowel disease (IBD) units. The aim of the study was to evaluate the impact of transition on IBD outcomes. (2) Methods: Multicentre, retrospective and observational study of IBD paediatric patients transferred to an adult IBD unit between 2017-2020. Two groups were compared: transition (≥1 joint visit involving the gastroenterologist, the paediatrician, a programme coordinator, the parents and the patient) and no-transition. Outcomes within one year after transfer were analysed. The main variable was poor clinical outcome (IBD flare, hospitalisation, surgery or any change in the treatment because of a flare). Predictive factors of poor clinical outcome were identified with multivariable analysis. (3) Results: A total of 278 patients from 34 Spanish hospitals were included. One hundred eighty-five patients (67%) from twenty-two hospitals (65%) performed a structured transition. Eighty-nine patients had poor clinical outcome at one year after transfer: 27% in the transition and 43% in the no-transition group (p = 0.005). One year after transfer, no-transition patients were more likely to have a flare (36% vs. 22%; p = 0.018) and reported more hospitalisations (10% vs. 3%; p = 0.025). The lack of transition, as well as parameters at transfer, including IBD activity, body mass index < 18.5 and corticosteroid treatment, were associated with poor clinical outcome. One patient in the transition group (0.4%) was lost to follow-up. (4) Conclusion: Transition care programmes improve patients' outcomes after the transfer from paediatric to adult IBD units. Active IBD at transfer impairs outcomes.

CAMT in a female with developmental delay, facial malformations and central nervous system anomalies.

Congenital amegakaryocytic thrombocytopenia (CAMT) is a rare disorder characterized by thrombocytopenia and absence or decline in the number of megakaryocytic precursors in the bone marrow. It is caused by mutations in the thrombopoietin receptor gene, c-mpl, involved in the proliferation and differentiation of megakaryocytes and platelets. The association between CAMT and central nervous system (CNS) anomalies has been reported in the literature, albeit not very frequently. Here we present a unique case where CAMT appeared associated to cerebellum agenesis, hypoplasia of the corpus callosum and brainstem, facial malformations, and developmental delay.

Prospective evaluation of indirect costs due to acute rotavirus gastroenteritis in Spain: the ROTACOST study.

BACKGROUND: The effect of rotavirus in developed countries is mainly economic. This study aimed to assess the indirect costs induced by rotavirus acute gastroenteritis (RVAGE) in Spain. METHODS: A prospective observational study was conducted from October 2008 to June 2009. It included 682 children up to 5 years of age with acute gastroenteritis (AGE) who attended primary care (n = 18) and emergency room/hospital settings (n = 10), covering the regions of Galicia and Asturias (North-west Spain). All non-medical expenses incurred throughout the episode were recorded in detail using personal interviews and telephone contact. RESULTS: Among the 682 enrolled children, 207 (30.4%) were rotavirus positive and 170 (25%) had received at least one dose of rotavirus vaccine. The mean (standard deviation) indirect cost caused by an episode of AGE was estimated at 135.17 (182.70) Euros. Costs were 1.74-fold higher when AGE was caused by rotavirus compared with other etiologies: 192.7 (219.8) Euros vs. 111.6 (163.5) Euros (p < .001). The costs for absenteeism were the most substantial with a mean of 91.41 (134.76) Euros per family, resulting in a loss of 2.45 (3.17) days of work. In RVAGE patients, the absenteeism cost was 120.4 (154) Euros compared with 75.8 (123) for the other etiologies (p = .002), because of loss of 3.5 (3.6) vs 1.9 (2.9) days of work (p < .001). Meals costs were 2-fold-higher (48.5 (55) vs 24.3 (46) Euros, p < .001) and travel costs were 2.6-fold-higher (32 (92) vs 12.5 (21.1) Euros, p = .005) in RVAGE patients compared with those with other etiologies. There were no differences between RVAGE and other etiologies groups regarding costs of hiring of caregivers or purchase of material. Patients with RVAGE were admitted to hospital more frequently than those with other etiologies (47.8% vs 14%, p < .001). CONCLUSIONS: Rotavirus generates a significant indirect economic burden. Our data should be considered in the decision-making process of the eventual inclusion of rotavirus vaccine in the national immunization schedule of well developed countries.

Letter to the editor concerning the article 'Safety of vaccines administration in hereditary fructose intolerance'.

The most important approach for the management of hereditary fructose intolerance is a strict avoidance of fructose, sucrose and sorbitol from the diet and medications. A safe threshold of 2.4 mg/kg/dose was recently established by the Instituto Superiore di Sanità of Italy for both oral and parenteral routes, thus shouldering a safe administration of a majority of vaccines in these patients. This would not include, Rotarix® pre-established oral suspension and Rotateq® vaccines, which are indeed contraindicated. Moreover, Rotarix® white powder and solvent for oral suspension would only be safely administered at a weight above 9.3 kg.Overall, these recommendations to avoid rotavirus vaccination are difficult to implement because these vaccines are given during exclusive breastfeeding, prior to fructose-containing food introduction.

Baby-Led Weaning: What Role Does It Play in Obesity Risk during the First Years? A Systematic Review.

Childhood is a window of opportunity for the prevention of the obesity pandemic. Since "the first 1000 days of life" is a period in which healthy eating habits must be acquired, it should be the target for preventive strategies. Baby-led weaning (BLW) is an emergent way of weaning that could influence children's health. The nutrition committees of the main pediatric societies affirm there is not enough evidence to support which is the best method of weaning. The aim was to determinate the influence of BLW on the infant's weight gain compared to the traditional spoon-feeding, and to assess if it could decrease the risk of obesity in children. A systematic review was conducted, following the PRISMA method. Pubmed, Web of Science, Embase, and Cochrane Library were searched. Out of 747 articles, eight studies (2875 total infants) were included (two randomized control trials, 6 observational studies). Results were indecisive, while some studies seem to demonstrate lower weight gain in infants that apply BLW, others show inconclusive results. The risk of bias in all included studies was moderate or high. In conclusion, more clinical trials and prospective studies should be done prior to providing a general recommendation about the best method of weaning to reduce the risk of obesity.

Reply letter to "safety of SARS-Cov-2 vaccines administration for adult patients with hereditary fructose intolerance".

In the letter, Urro et al. performed a search on the sucrose, fructose and sorbitol content in the approved Sars-Cov-2 vaccines and they concluded that these vaccines can be safely administered in adults affected by Hereditary fructose intolerance.The Pfizer-BioNTech COVID-19 Vaccine is currently approved for use in adolescents ≥ 12 years and the Moderna COVID-19 vaccine is close to approval for use in children over 12 years of age. Furthermore, both vaccines have initiated clinical trials that will include infant as young as 6 months. Therefore, we considerate important to analyze the safely administration of this two vaccines in children with Hereditary fructose intolerance.

Predictors of Response to Exclusive Enteral Nutrition in Newly Diagnosed Crohn´s Disease in Children: PRESENCE Study from SEGHNP.

Exclusive enteral nutrition (EEN) has been shown to be more effective than corticosteroids in achieving mucosal healing in children with Crohn´s disease (CD) without the adverse effects of these drugs. The aims of this study were to determine the efficacy of EEN in terms of inducing clinical remission in children newly diagnosed with CD, to describe the predictive factors of response to EEN and the need for treatment with biological agents during the first 12 months of the disease. We conducted an observational retrospective multicentre study that included paediatric patients newly diagnosed with CD between 2014-2016 who underwent EEN. Two hundred and twenty-two patients (140 males) from 35 paediatric centres were included, with a mean age at diagnosis of 11.6 ± 2.5 years. The median EEN duration was 8 weeks (IQR 6.6-8.5), and 184 of the patients (83%) achieved clinical remission (weighted paediatric Crohn's Disease activity index [wPCDAI] < 12.5). Faecal calprotectin (FC) levels (µg/g) decreased significantly after EEN (830 [IQR 500-1800] to 256 [IQR 120-585] p < 0.0001). Patients with wPCDAI ≤ 57.5, FC < 500 µg/g, CRP >15 mg/L and ileal involvement tended to respond better to EEN. EEN administered for 6-8 weeks is effective for inducing clinical remission. Due to the high response rate in our series, EEN should be used as the first-line therapy in luminal paediatric Crohn's disease regardless of the location of disease and disease activity.

NEmecum: herramienta digital de ayuda a la prescripción y dispensación de fórmulas de nutrición enteral y preparados infantiles / NEmecum: digital tool for assisting in the prescription and dispensing of enteral nutrition formulas and infant preparations

Introducción: existe una amplia variedad de fórmulas o preparados de nutrición enteral y fórmulas o preparados infantiles. La consulta de información relacionada debe hacerse en las herramientas propias de cada laboratorio, lo que dificulta la visión crítica y la comparativa entre las mismas. Objetivo: describir el desarrollo de NEmecum como la primera web que permite realizar una búsqueda dirigida e independiente de fórmulas de nutrición o preparados infantiles, analizar el abanico nutricional actual en España y evaluar los datos de uso de la herramienta. Métodos: se desarrolló la estructura de una base de datos que unifica los parámetros de todas las fórmulas y se analizó el abanico nutricional español. Posteriormente, se seleccionaron los principales algoritmos de búsqueda dirigida y se codificó la herramienta digital. Se llevó a cabo una intensa difusión y se evaluó el impacto obtenido. Se analizaron el perfil de usuarios y centros registrados y los datos de uso de la herramienta y se evaluó su usabilidad mediante el cuestionario System Usability Scale (SUS). Resultados: se obtuvo una web responsive de acceso gratuito (http://nemecum.com) que permite realizar búsquedas dirigidas en base a unos filtros de búsqueda preestablecidos. La herramienta permitió analizar detalladamente el abanico nutricional en España, observándose la gran variedad de fórmulas disponibles de similares características. La campaña de difusión consiguió incrementar su uso de forma exponencial y cuenta actualmente con 1.370 usuarios y 79 centros registrados. La usabilidad fue valorada como excelente. Conclusión: el desarrollo de NEmecum supone una herramienta valiosa en la búsqueda y consulta de datos de fórmulas o preparados de nutrición enteral y fórmulas o preparados infantiles. (AU)

Introduction: there is a wide variety of enteral nutrition and infant formulas preparations. When there is a need to find infomation on a product,only the infomation from industy is available. Comparison amomg products becomes then ardous.Objective: to describe the development of NEmecum as the first website that allows a directed and independent search for enteral nutritionproducts and infant formulas, currently available in Spain, and to evaluate the initial use of NEmecum.Methods: the structure of a database that unifies the parameters of all formulas was developed, and the nutritional composition of all formulaswas analyzed. Subsequently, the main search algorithms were selected and the digital tool was codified. Intensive dissemination was performedand the impact was evaluated. The profile of users and registered centers and the use of the tool were analyzed, and its usability was evaluatedusing the System Usability Scale (SUS) questionnaire.Results: a free-access responsive website (http://nemecum.com) that allows searches based on pre-established search filters was obtained. Thistool allows for a detailed analysis available formulas in Spain by observing a wide variety of formulas with similar characteristics. The disseminationcampaign managed to increase its use exponentially, currently reaching 1,370 users and 79 registered centers. Usability was rated as excellent.Conclusion: the development of the NEmecum represents a valuable tool in the search and consultation of the characteristics of enteral nutritionformulas and infant preparations. (AU)

Bacteremia in Children Hospitalized with Respiratory Syncytial Virus Infection.

BACKGROUND: The risk of bacteremia is considered low in children with acute bronchiolitis. However the rate of occult bacteremia in infants with RSV infection is not well established. The aim was to determine the actual rate and predictive factors of bacteremia in children admitted to hospital due to confirmed RSV acute respiratory illness (ARI), using both conventional culture and molecular techniques. METHODS: A prospective multicenter study (GENDRES-network) was conducted between 2011-2013 in children under the age of two admitted to hospital because of an ARI. Among those RSV-positive, bacterial presence in blood was assessed using PCR for Meningococcus, Streptococcus pneumoniae, Haemophilus influenzae, Streptococcus pyogenes, Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus, in addition to conventional cultures. RESULTS: 66 children with positive RSV respiratory illness were included. In 10.6% patients, bacterial presence was detected: H. influenzae (n = 4) and S. pneumoniae (n = 2). In those patients with bacteremia, there was a previous suspicion of bacterial superinfection and had received empirical antibiotic treatment 6 out of 7 (85.7%) patients. There were significant differences in terms of severity between children with positive bacterial PCR and those with negative results: PICU admission (100% vs. 50%, P-value = 0.015); respiratory support necessity (100% vs. 18.6%, P-value < 0.001); Wood-Downes score (mean = 8.7 vs. 4.8 points, P-value < 0.001); GENVIP scale (mean = 17 vs. 10.1, P-value < 0.001); and length of hospitalization (mean = 12.1 vs. 7.5 days, P-value = 0.007). CONCLUSION: Bacteremia is not frequent in infants hospitalized with RSV respiratory infection, however, it should be considered in the most severe cases.

Does Viral Co-Infection Influence the Severity of Acute Respiratory Infection in Children?

BACKGROUND: Multiple viruses are often detected in children with respiratory infection but the significance of co-infection in pathogenesis, severity and outcome is unclear. OBJECTIVES: To correlate the presence of viral co-infection with clinical phenotype in children admitted with acute respiratory infections (ARI). METHODS: We collected detailed clinical information on severity for children admitted with ARI as part of a Spanish prospective multicenter study (GENDRES network) between 2011-2013. A nested polymerase chain reaction (PCR) approach was used to detect respiratory viruses in respiratory secretions. Findings were compared to an independent cohort collected in the UK. RESULTS: 204 children were recruited in the main cohort and 97 in the replication cohort. The number of detected viruses did not correlate with any markers of severity. However, bacterial superinfection was associated with increased severity (OR: 4.356; P-value = 0.005), PICU admission (OR: 3.342; P-value = 0.006), higher clinical score (1.988; P-value = 0.002) respiratory support requirement (OR: 7.484; P-value < 0.001) and longer hospital length of stay (OR: 1.468; P-value < 0.001). In addition, pneumococcal vaccination was found to be a protective factor in terms of degree of respiratory distress (OR: 2.917; P-value = 0.035), PICU admission (OR: 0.301; P-value = 0.011), lower clinical score (-1.499; P-value = 0.021) respiratory support requirement (OR: 0.324; P-value = 0.016) and oxygen necessity (OR: 0.328; P-value = 0.001). All these findings were replicated in the UK cohort. CONCLUSION: The presence of more than one virus in hospitalized children with ARI is very frequent but it does not seem to have a major clinical impact in terms of severity. However bacterial superinfection increases the severity of the disease course. On the contrary, pneumococcal vaccination plays a protective role.

Natural resistance to Meningococcal Disease related to CFH loci: Meta-analysis of genome-wide association studies.

Meningococcal disease (MD) remains an important infectious cause of life threatening infection in both industrialized and resource poor countries. Genetic factors influence both occurrence and severity of presentation, but the genes responsible are largely unknown. We performed a genome-wide association study (GWAS) examining 5,440,063 SNPs in 422 Spanish MD patients and 910 controls. We then performed a meta-analysis of the Spanish GWAS with GWAS data from the United Kingdom (combined cohorts: 897 cases and 5,613 controls; 4,898,259 SNPs). The meta-analysis identified strong evidence of association (P-value ≤ 5 × 10-8) in 20 variants located at the CFH gene. SNP rs193053835 showed the most significant protective effect (Odds Ratio (OR) = 0.62, 95% confidence interval (C.I.) = 0.52-0.73; P-value = 9.62 × 10-9). Five other variants had been previously reported to be associated with susceptibility to MD, including the missense SNP rs1065489 (OR = 0.64, 95% C.I.) = 0.55-0.76, P-value = 3.25 × 10-8). Theoretical predictions point to a functional effect of rs1065489, which may be directly responsible for protection against MD. Our study confirms the association of CFH with susceptibility to MD and strengthens the importance of this link in understanding pathogenesis of the disease.

Impact of Rotavirus Vaccination on Childhood Hospitalization for Seizures.

BACKGROUND: Rotavirus vaccine (RV) might reduce the risk of hospitalization due to childhood seizures (CS). We aimed to identify and assess variations in the incidence of hospitalizations for CS among children <5 years of age before and after RV introduction. METHODS: Annual hospitalization rates for any kind of CS, before and after RV introduction in 2007, were calculated using the official surveillance system for hospitalization data. RESULTS: Our study cohort totaled 6149 children <5 years of age admitted to the hospital between 2003 and 2013 with any kind of CS (780.3* + 779.0* + 333.2* + 345* ICD-9-CM code). The annual hospitalization rates for any kind of CS in children <5 years of age were correlated with RV coverage (r = -0.673; P = 0.033) and rotavirus acute gastroenteritis admission rates (ρ = 0.506; P = 0.001), with decrease rates ranging from 16.2% (95% confidence interval: 8.3-23.5%) in 2007 to 34.0% (27.3-40.1%) in 2010, as compared with the median rate of the pre-vaccination period (2003 to 2006). Similarly, for convulsions (780.3*ICD-9-CM code), the decrease seen in children <5 years of age was significantly correlated with the increase in RV coverage (r = -0.747; P = 0.013) and rotavirus acute gastroenteritis admission rates (ρ = 0.543; P < 0.001), with decrease rates ranging from 18.7% (9.6-26.8%) in 2007 to 42.5% (35.3-48.9%) in 2012. Significant results were also obtained for infants <12 months and infants 1-2 years of age. In the remaining age groups or diagnostic categories analyzed, changes were either not significant or not related to vaccination changes or rotavirus acute gastroenteritis admission rates. CONCLUSIONS: Our results show that rotavirus vaccination may have a significant impact in the decrease in seizure-related hospitalizations in childhood. This additional benefit of rotavirus vaccination seems more marked in the youngest infants.

Viral Co-Infections in Pediatric Patients Hospitalized with Lower Tract Acute Respiratory Infections.

BACKGROUND: Molecular techniques can often reveal a broader range of pathogens in respiratory infections. We aim to investigate the prevalence and age pattern of viral co-infection in children hospitalized with lower tract acute respiratory infection (LT-ARI), using molecular techniques. METHODS: A nested polymerase chain reaction approach was used to detect Influenza (A, B), metapneumovirus, respiratory syncytial virus (RSV), parainfluenza (1-4), rhinovirus, adenovirus (A-F), bocavirus and coronaviruses (NL63, 229E, OC43) in respiratory samples of children with acute respiratory infection prospectively admitted to any of the GENDRES network hospitals between 2011-2013. The results were corroborated in an independent cohort collected in the UK. RESULTS: A total of 204 and 97 nasopharyngeal samples were collected in the GENDRES and UK cohorts, respectively. In both cohorts, RSV was the most frequent pathogen (52.9% and 36.1% of the cohorts, respectively). Co-infection with multiple viruses was found in 92 samples (45.1%) and 29 samples (29.9%), respectively; this was most frequent in the 12-24 months age group. The most frequently observed co-infection patterns were RSV-Rhinovirus (23 patients, 11.3%, GENDRES cohort) and RSV-bocavirus / bocavirus-influenza (5 patients, 5.2%, UK cohort). CONCLUSION: The presence of more than one virus in pediatric patients admitted to hospital with LT-ARI is very frequent and seems to peak at 12-24 months of age. The clinical significance of these findings is unclear but should warrant further analysis.

Enfermedad celíaca y gastritis colágena, una asociación infrecuente en la infancia / Celiac disease and collagenous gastritis: A rare combination in childhood

No disponible

Indian signatures in the westernmost edge of the European Romani diaspora: new insight from mitogenomes.

In agreement with historical documentation, several genetic studies have revealed ancestral links between the European Romani and India. The entire mitochondrial DNA (mtDNA) of 27 Spanish Romani was sequenced in order to shed further light on the origins of this population. The data were analyzed together with a large published dataset (mainly hypervariable region I [HVS-I] haplotypes) of Romani (N=1,353) and non-Romani worldwide populations (N>150,000). Analysis of mitogenomes allowed the characterization of various Romani-specific clades. M5a1b1a1 is the most distinctive European Romani haplogroup; it is present in all Romani groups at variable frequencies (with only sporadic findings in non-Romani) and represents 18% of their mtDNA pool. Its phylogeographic features indicate that M5a1b1a1 originated 1.5 thousand years ago (kya; 95% CI: 1.3-1.8) in a proto-Romani population living in Northwest India. U3 represents the most characteristic Romani haplogroup of European/Near Eastern origin (12.4%); it appears at dissimilar frequencies across the continent (Iberia: ≈ 31%; Eastern/Central Europe: ≈ 13%). All U3 mitogenomes of our Iberian Romani sample fall within a new sub-clade, U3b1c, which can be dated to 0.5 kya (95% CI: 0.3-0.7); therefore, signaling a lower bound for the founder event that followed admixture in Europe/Near East. Other minor European/Near Eastern haplogroups (e.g. H24, H88a) were also assimilated into the Romani by introgression with neighboring populations during their diaspora into Europe; yet some show a differentiation from the phylogenetically closest non-Romani counterpart. The phylogeny of Romani mitogenomes shows clear signatures of low effective population sizes and founder effects. Overall, these results are in good agreement with historical documentation, suggesting that cultural identity and relative isolation have allowed the Romani to preserve a distinctive mtDNA heritage, with some features linking them unequivocally to their ancestral Indian homeland.