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result(s) for
"Perez, Ana B A"
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Patients with a Kabuki syndrome phenotype demonstrate DNA methylation abnormalities
by
Ongaco, Chrissie
,
Doheny, Kimberly F
,
Perez, Ana BA
in
Abnormalities, Multiple - diagnosis
,
Abnormalities, Multiple - genetics
,
Case-Control Studies
2017
Kabuki syndrome is a monogenic disorder caused by loss of function variants in either of two genes encoding histone-modifying enzymes. We performed targeted sequencing in a cohort of 27 probands with a clinical diagnosis of Kabuki syndrome. Of these, 12 had causative variants in the two known Kabuki syndrome genes. In 2, we identified presumptive loss of function de novo variants in KMT2A (missense and splice site variants), a gene that encodes another histone modifying enzyme previously exclusively associated with Wiedermann-Steiner syndrome. Although Kabuki syndrome is a disorder of histone modification, we also find alterations in DNA methylation among individuals with a Kabuki syndrome diagnosis relative to matched normal controls, regardless of whether they carry a variant in KMT2A or KMT2D or not. Furthermore, we observed characteristic global abnormalities of DNA methylation that distinguished patients with a loss of function variant in KMT2D or missense or splice site variants in either KMT2D or KMT2A from normal controls. Our results provide new insights into the relationship of genotype to epigenotype and phenotype and indicate cross-talk between histone and DNA methylation machineries exposed by inborn errors of the epigenetic apparatus.
Journal Article
Marfan syndrome with a complex chromosomal rearrangement including deletion of the FBN1 gene
by
N Dutra, Ana R
,
da Silva, Luciana RJ
,
Mancini, Tatiane I
in
Biomedical and Life Sciences
,
Biomedicine
,
Breakpoints
2012
Background
The majority of Marfan syndrome (MFS) cases is caused by mutations in the fibrillin-1 gene (
FBN1
), mapped to chromosome 15q21.1. Only few reports on deletions including the whole
FBN1
gene, detected by molecular cytogenetic techniques, were found in literature.
Results
We report here on a female patient with clinical symptoms of the MFS spectrum plus craniostenosis, hypothyroidism and intellectual deficiency who presents a 1.9 Mb deletion, including the
FBN1
gene and a complex rearrangement with eight breakpoints involving chromosomes 6, 12 and 15.
Discussion
This is the first report of MFS with a complex chromosome rearrangement involving a deletion of
FBN1
and contiguous genes. In addition to the typical clinical findings of the Marfan syndrome due to
FBN1
gene haploinsufficiency, the patient presents features which may be due to the other gene deletions and possibly to the complex chromosome rearrangement.
Journal Article
A novel de novo mutation in MYT1, the unique OAVS gene identified so far
by
Bragagnolo, Silvia
,
Rooryck, Caroline
,
Melaragno, Maria I
in
Child
,
Child, Preschool
,
Developmental disabilities
2017
Oculo-auriculo-vertebral spectrum (OAVS) is a developmental disorder characterized by hemifacial microsomia associated with ear, eyes and vertebrae malformations showing highly variable expressivity. Recently, MYT1, encoding the myelin transcription factor 1, was reported as the first gene involved in OAVS, within the retinoic acid (RA) pathway. Fifty-seven OAVS patients originating from Brazil were screened for MYT1 variants. A novel de novo missense variant affecting function, c.323C>T (p.(Ser108Leu)), was identified in MYT1, in a patient presenting with a severe form of OAVS. Functional studies showed that MYT1 overexpression downregulated all RA receptors genes (RARA, RARB, RARG), involved in RA-mediated transcription, whereas no effect was observed on CYP26A1 expression, the major enzyme involved in RA degradation, Moreover, MYT1 variants impacted significantly the expression of these genes, further supporting their pathogenicity. In conclusion, a third variant affecting function in MYT1 was identified as a cause of OAVS. Furthermore, we confirmed MYT1 connection to RA signaling pathway.
Journal Article
Atypical 581-kb 22q11.21 Deletion in a Patient with Oculo-Auriculo-Vertebral Spectrum Phenotype
by
Dantas, Anelisa G.
,
Bragagnolo, Silvia
,
Soares, Maria F.
in
Abnormalities, Multiple - genetics
,
Abnormalities, Multiple - pathology
,
Child, Preschool
2015
The oculo-auriculo-vertebral spectrum (OAVS) is defined as a group of malformations involving the ears, mouth, mandible, eyes, and cervical spine. Establishing an accurate clinical diagnosis of OAVS is a challenge for clinical geneticists, not only because these patients display heterogeneous phenotypes, but also because its etiology encompasses environmental factors, unknown genetic factors and different chromosome aberrations. To date, several chromosomal abnormalities have been associated with the syndrome, most frequently involving chromosome 22. In the literature, six 22q11.2 microdeletions have been described within the same region, suggesting possible OAVS candidate genes in this segment. Here, we report on a patient with an ∼581-kb 22q11.21 deletion, detected by genomic array and MLPA. This is the 7th case described with OAVS and 22q deletion, suggesting that the 22q11.2 region may be related to the regulation of body symmetry and facial development.
Journal Article
Serum Total Homocysteine Levels and the Prevalence of Folic Acid Deficiency and C677T Mutation at the MTHFR Gene in an Indigenous Population of Amazonia
by
Vieira-Filho, João P. B.
,
Tavares, Edelweiss F.
,
Andriolo, Adagmar
in
Adult
,
Brazil - epidemiology
,
Cardiovascular Diseases - ethnology
2004
Hyperhomocysteinemia is a risk factor for cardiovascular disease. C677T mutation at the MTHFR gene and deficiencies of folic acid and vitamin B-12 may account for elevation of total homocysteine (tHcy). Ninety Brazilian Parkatêjê Indians (90.0% of the population without admixture, aged ≥20 years) were studied. Hyperhomocysteinemia was observed in 26.7% of the Indians. No case of vitamin B-12 deficiency was detected. Folic acid deficiency was found in 43.3% of the subjects. Rates of mutated allele 677T and TT genotype were 40.7% and 14.0%, respectively. Prevalence of hypertension, dyslipidemia, smoking, WHR ≥0.9, BMI ≥25 kg/m² and chronic alcohol use were 4.4%, 44.4%, 25.6%, 72.2%, 67.8%, and 0.0%, respectively. All creatinine values were normal. Natural logarithmic (ln) tHcy showed no correlation with age, but was positively correlated with systolic (r=0.22) and diastolic (r=0.21) blood pressure and triglycerides (r=0.39) and inversely correlated with folic acid (r=–0.40) adjusted for age and sex. Total homocysteine (tHcy) was higher among TT genotype (P<.001). The multiple linear regression model, containing variables for sex, folic acid, TT genotype, and triglycerides, explained 50.0% of the variation of the ln tHcy. In summary, high rates of cardiovascular risk factors were discovered. C667T mutation and folic acid deficiency can explain, at least in part, the observed hyperhomocysteinemia.
Journal Article
For the Patient: Risk Factors for Heart Disease
by
Andriolo, Adagmar
,
Franco, Laérco J
,
Sañudo, Adriana
in
Cardiovascular Disease
,
Comparative analysis
,
Ethnicity
2003
This study was conducted on Brazilian Indian groups age 20 or older to determine risk factors present for cardiovasular disease. Findings are discussed.
Journal Article
Original Reports: Cardiovascular Health--Serum Total Homocysteine Levels and the Prevalence of Folic Acid Deficiency and C677T Mutation at the MTHFR Gene in an Indigenous Population of Amazonia: The Relationship of Homocysteine with other Cardiovascular Risk Factors
by
Andriolo, Adagmar
,
Sañudo, Adriana
,
Vargani, Naja
in
Cardiovascular Disease
,
Health and Medicine
,
Health Risk Assessment
2003
A study of 90 indigenous Brazilians around the age of 20 were examined for deficiancy of folic acid and the possible risk of cardiovascular disease.
Journal Article
OSBPL10, RXRA and lipid metabolism confer African-ancestry protection against dengue haemorrhagic fever in admixed Cubans
by
Cavadas, Bruno
,
Garcia, Gissel
,
Regnault, Béatrice
in
African Continental Ancestry Group
,
African Continental Ancestry Group - genetics
,
Bioinformatics
2017
Ethnic groups can display differential genetic susceptibility to infectious diseases. The arthropod-born viral dengue disease is one such disease, with empirical and limited genetic evidence showing that African ancestry may be protective against the haemorrhagic phenotype. Global ancestry analysis based on high-throughput genotyping in admixed populations can be used to test this hypothesis, while admixture mapping can map candidate protective genes. A Cuban dengue fever cohort was genotyped using a 2.5 million SNP chip. Global ancestry was ascertained through ADMIXTURE and used in a fine-matched corrected association study, while local ancestry was inferred by the RFMix algorithm. The expression of candidate genes was evaluated by RT-PCR in a Cuban dengue patient cohort and gene set enrichment analysis was performed in a Thai dengue transcriptome. OSBPL10 and RXRA candidate genes were identified, with most significant SNPs placed in inferred weak enhancers, promoters and lncRNAs. OSBPL10 had significantly lower expression in Africans than Europeans, while for RXRA several SNPs may differentially regulate its transcription between Africans and Europeans. Their expression was confirmed to change through dengue disease progression in Cuban patients and to vary with disease severity in a Thai transcriptome dataset. These genes interact in the LXR/RXR activation pathway that integrates lipid metabolism and immune functions, being a key player in dengue virus entrance into cells, its replication therein and in cytokine production. Knockdown of OSBPL10 expression in THP-1 cells by two shRNAs followed by DENV2 infection tests led to a significant reduction in DENV replication, being a direct functional proof that the lower OSBPL10 expression profile in Africans protects this ancestry against dengue disease.
Journal Article
Using Smartphones and Wearable Devices to Monitor Behavioral Changes During COVID-19
2020
In the absence of a vaccine or effective treatment for COVID-19, countries have adopted nonpharmaceutical interventions (NPIs) such as social distancing and full lockdown. An objective and quantitative means of passively monitoring the impact and response of these interventions at a local level is needed.
We aim to explore the utility of the recently developed open-source mobile health platform Remote Assessment of Disease and Relapse (RADAR)-base as a toolbox to rapidly test the effect and response to NPIs intended to limit the spread of COVID-19.
We analyzed data extracted from smartphone and wearable devices, and managed by the RADAR-base from 1062 participants recruited in Italy, Spain, Denmark, the United Kingdom, and the Netherlands. We derived nine features on a daily basis including time spent at home, maximum distance travelled from home, the maximum number of Bluetooth-enabled nearby devices (as a proxy for physical distancing), step count, average heart rate, sleep duration, bedtime, phone unlock duration, and social app use duration. We performed Kruskal-Wallis tests followed by post hoc Dunn tests to assess differences in these features among baseline, prelockdown, and during lockdown periods. We also studied behavioral differences by age, gender, BMI, and educational background.
We were able to quantify expected changes in time spent at home, distance travelled, and the number of nearby Bluetooth-enabled devices between prelockdown and during lockdown periods (P<.001 for all five countries). We saw reduced sociality as measured through mobility features and increased virtual sociality through phone use. People were more active on their phones (P<.001 for Italy, Spain, and the United Kingdom), spending more time using social media apps (P<.001 for Italy, Spain, the United Kingdom, and the Netherlands), particularly around major news events. Furthermore, participants had a lower heart rate (P<.001 for Italy and Spain; P=.02 for Denmark), went to bed later (P<.001 for Italy, Spain, the United Kingdom, and the Netherlands), and slept more (P<.001 for Italy, Spain, and the United Kingdom). We also found that young people had longer homestay than older people during the lockdown and fewer daily steps. Although there was no significant difference between the high and low BMI groups in time spent at home, the low BMI group walked more.
RADAR-base, a freely deployable data collection platform leveraging data from wearables and mobile technologies, can be used to rapidly quantify and provide a holistic view of behavioral changes in response to public health interventions as a result of infectious outbreaks such as COVID-19. RADAR-base may be a viable approach to implementing an early warning system for passively assessing the local compliance to interventions in epidemics and pandemics, and could help countries ease out of lockdown.
Journal Article