Publications by authors named "Rachel S Honjo"

Lysosomal acid lipase deficiency (LALD) varies from a severe infantile-onset form (Wolman disease) to a late-onset form known as cholesteryl ester storage disease (CESD), both of which are autosomal recessive disorders caused by biallelic pathogenic variants. We evaluated seventy-three patients enlisted for liver transplant (LT) at Instituto da Criança (HCFMUSP-Brazil) who were subjected to LAL activity measurement and Sanger sequencing analysis, resulting in a positive LALD diagnosis for only one of these individuals. This LALD patient presented recurrent diarrhea, failure to thrive, hepatomegaly, and dyslipidemia at the age of 4 months and liver failure by the age of 13 years.

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Objective: to report the first case series of Brazilian children diagnosed with Kleefstra syndrome, present a possible phenotype expansion to the syndrome and to raise physicians' awareness for this rare disease.

Results: seven patients with confirmed KS were evaluated, including 5 males and 2 females. Abnormal prenatal findings were observed in 4 patients.

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This manuscript reviewed the state of the art about the teaching and training of human resources for genetics and genomics in Brazil. We presented the national scenario of teaching genetics in medical undergraduate and other health courses. We discussed the training of medical geneticists through medical residency and addressed the training in genetics of physicians from specialties other than genetics.

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Background: Epidermolysis bullosa (EB) is characterized by skin fragility and blistering. In Brazil, the diagnosis is usually obtained through immunomapping, which involves a skin biopsy. Most recently, whole exome sequencing (WES) has become an important tool for the diagnosis of the subtypes of EB, providing information on prognosis as well as allowing appropriate genetic counseling for the families.

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Article Synopsis
  • - The study evaluated the use of whole genome sequencing (WGS) as a first-step diagnostic tool for critically ill infants in Brazilian neonatal intensive care units, with collaboration between private and public hospitals.
  • - In a cohort of 21 infants suspected of genetic diseases, WGS provided a diagnostic yield of 57%, identifying various genetic variants, including 10 novel ones not found in existing databases.
  • - The research highlighted the advantages of WGS over traditional genetic tests in diagnosing conditions like dysmorphic syndromes while also discussing the challenges and potential implications of integrating WGS into Brazil's healthcare system.
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The gene for ATP binding cassette subfamily A member 2 (ABCA2) is located at chromosome 9q34.3. Biallelic ABCA2 variants lead to intellectual developmental disorder with poor growth and with or without seizures or ataxia (IDPOGSA).

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Objective: To develop growth charts for weight-for-age, height-for-age, and body mass index (BMI)-for-age for both genders aged 2 to 18 years for Brazilian patients with Williams-Beuren Syndrome (WBS).

Methods: This is a multicenter, retrospective, and longitudinal study, data were collected from the medical records of boys and girls with a confirmed diagnosis of WBS in three large university centers in the state of Sao Paulo, Brazil. Growth charts stratified by gender and age in years were developed using LMSchartmaker Pro software.

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Microcephaly is characterized by an occipitofrontal circumference at least two standard deviations below the mean for age and sex. Neurodevelopmental disorders (NDD) are commonly associated with microcephaly, due to perturbations in brain development and functioning. Given the extensive genetic heterogeneity of microcephaly, managing patients is hindered by the broad spectrum of diagnostic possibilities that exist before conducting molecular testing.

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Background: The affective expression of sexual behaviour in individuals with Williams syndrome can lead to risky behaviours, especially if parents do not have information on how to provide sex education or support from specialised professionals.

Method: The Attitudes to Sexuality Questionnaire for Individuals with Intellectual Disabilities was used to identify parental beliefs, attitudes and concerns about the sexuality and sex education of individuals with intellectual disabilities. The sample comprised 35 parents of individuals with Williams syndrome (mean age 12.

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We discovered biallelic intragenic structural variations (SVs) in by applying long-read whole genome sequencing to an exome-negative patient with developmental and epileptic encephalopathy (DEE). We also found another DEE patient carrying a biallelic (homozygous) single-nucleotide variant (SNV) in that was detected by exome sequencing. heterozygous recurrent missense variants with gain-of-function or heterozygous entire duplication of are known causes of epilepsy, but biallelic SNVs/SVs have never been described.

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Article Synopsis
  • Rothmund-Thomson syndrome (RTS) is a rare genetic skin disorder characterized by poikiloderma and divided into two types based on genetic variations and symptoms.
  • A study of Brazilian individuals and European siblings with RTS revealed severe short stature, widespread poikiloderma, and congenital eye problems, linked to specific gene mutations affecting DNA repair.
  • The findings suggest a shared genetic background due to a founder effect and propose that the mutations may lead to distinct clinical characteristics, broadening the understanding of RTS symptoms.
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The SUZ12 gene encodes a subunit of polycomb repressive complex 2 (PRC2) that is essential for development by silencing the expression of multiple genes. Germline heterozygous variants in SUZ12 have been found in Imagawa-Matsumoto syndrome (IMMAS) characterized by overgrowth and multiple dysmorphic features. Similarly, both EZH2 and EED also encode a subunit of PRC2 each and their pathogenic variants cause Weaver syndrome and Cohen-Gibson syndrome, respectively.

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Article Synopsis
  • Microcephaly has a complex genetic background often linked to various neurodevelopmental disorders, with copy number variants (CNVs) identified as a key causal factor.
  • The study analyzed chromosomal microarray data from 185 Brazilian patients and found rare clinically relevant CNVs in 21% of cases, revealing several known and novel genes associated with microcephaly.
  • A comprehensive review of microcephaly-related genes and CNV syndromes was conducted, highlighting the importance of chromosomal microarray analysis in diagnosis and identifying new candidate loci for further investigation in neurodevelopmental research.
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Objective: To report the effectiveness of early molecular diagnosis in the clinical management of rare diseases, presenting 8 patients with 8p23.1DS who have clinical features that overlap the phenotypic spectrum of 22q11.2DS.

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Recent studies suggest that transcript isoforms significantly overlap (approximately 60%) between brain tissue and Epstein-Barr virus-transformed lymphoblastoid cell lines (LCLs). Interestingly, 14 cohesion-related genes with variants that cause Cornelia de Lange Syndrome (CdLS) are highly expressed in the brain and LCLs. In this context, we first performed RNA sequencing of LCLs from 22 solved (with pathogenic variants) and 19 unsolved (with no confirmed variants) CdLS cases.

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Background: Mucopolysaccharidosis type II, also known as Hunter syndrome, is a rare X-linked recessive disorder caused by deficiency of the lysosomal enzyme Iduronate-2- Sulfatase (IDS), leading to progressive accumulation of Glycosaminoglycans (GAGs) in several organs. Over the years, Enzyme Replacement Therapy (ERT) has provided significant benefits for patients, retarding the natural progression of the disease.

Results: The authors evaluated 17 patients from the same family with a mild form of MPS type II; the proband had developed acute decompensated heart failure refractory to clinical measurements at 23 years and needed a rather urgent heart transplant; however, he died from surgical complications shortly after the procedure.

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Robinow syndrome (RS) is a genetically heterogeneous disorder with six genes that converge on the WNT/planar cell polarity (PCP) signaling pathway implicated (, , , , , and ). RS is characterized by skeletal dysplasia and distinctive facial and physical characteristics. To further explore the genetic heterogeneity, paralog contribution, and phenotypic variability of RS, we investigated a cohort of 22 individuals clinically diagnosed with RS from 18 unrelated families.

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Osteogenesis imperfecta (OI) is a rare low-bone mass skeletal Mendelian disorder characterized by bone fragility leading to bone fractures, with deformities and stunted growth in the more severe phenotypes. Other common, nonskeletal findings include blue sclerae and dentinogenesis imperfecta. It is caused mainly by quantitative or structural defects in type I collagen, although dysregulation of different signaling pathways that play a role in bone morphogenesis has been described to be associated with a small fraction of individuals with OI.

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Background: Williams-Beuren syndrome is a multisystemic disorder caused by a microdeletion of the 7q11.23 region. Although familial cases with autosomal dominant inheritance have been reported, the vast majority are sporadic.

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Article Synopsis
  • - Williams-Beuren syndrome (WBS) is a rare genetic disorder marked by facial features, intellectual disability, a friendly demeanor, and significant cardiovascular issues, particularly supravalvular aortic stenosis (SVAS).
  • - A study of 127 WBS patients over 20 years found that 74% had cardiovascular defects, with nearly one-quarter requiring surgical procedures, including one case of heart transplantation due to severe heart failure.
  • - Cardiovascular complications are a leading cause of mortality in WBS patients, highlighting the importance of careful surgical planning, monitoring, and multidisciplinary care for those requiring heart surgeries.
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Holoprosencephaly (HPE) is the failure of the embryonic forebrain to develop into 2 hemispheres promoting midline cerebral and facial defects. The wide phenotypic variability and causal heterogeneity make genetic counseling difficult. Heterozygous variants with incomplete penetrance and variable expressivity in the , , , and genes explain ∼25% of the known causes of nonchromosomal HPE.

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Sotos syndrome is characterized by overgrowth starting before birth through childhood with intellectual disability and craniofacial anomalies. The majority of patients are large for gestational age with developmental delay or intellectual disability. The majority of cases are caused by pathogenic variants in NSD1.

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Congenital limb deficiency (CLD), one of the most common congenital anomalies, is characterized by hypoplasia/aplasia of one or more limb bones and can be isolated or syndromic. The etiology in CLD is heterogeneous, including environmental and genetic factors. A fraction remains with no etiological factor identified.

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Noonan syndrome (NS) is a Mendelian phenotype, member of a group of disorders sharing neurocardiofaciocutaneous involvement, known as RASopathies, caused by germline variants in genes coding for components of the RAS/MAPK signaling pathway. Recently, a novel gene of the RAS family (MRAS) was reported to be associated with NS in five children, all of them presenting, among the cardinal features of NS, the same cardiac finding, hypertrophic cardiomyopathy (HCM). We report on a 2-month-old infant boy also presenting this cardiac anomaly that evolved to a fatal outcome after a surgical myectomy.

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