An adult with cystathionine beta-synthase deficiency, camptodactyly-arthropathy-coxa vara-pericarditis syndrome, and deafness: A case report.

Massive sequencing platforms allow the identification of complex clinical phenotypes involving more than one autosomal recessive disorder. In this study, we report on an adult patient, born to a related couple (third degree cousins), referred for genetic evaluation due to ectopia lentis, deafness and previous diagnosis of juvenile idiopathic arthritis. He was biochemically diagnosed as having Classic Homocystinuria (HCU); Sanger sequencing of the CBS gene showed the genotype NM_000071.2(CBS):c.[833T>C];[833T>C], compatible with the diagnosis of pyridoxine-responsive HCU. As he also had symptoms not usually associated with HCU, exome sequencing was performed. In addition to the variants found in the Sanger sequencing, the following variants were identified: NM_001256317.1(TMPRSS3):c.[413C>A];[413C>A]; and the NM_005807.6(PRG4):c.[3756dup]:[3756dup], confirming the diagnosis of autosomal recessive nonsyndromic deafness and Camptodactyly-Arthropathy-Coxa Vara-Pericarditis Syndrome (CACP), respectively. Genomic analysis allowed the refinement of the diagnosis of a complex case and improvement of the patient's treatment.

Disease progression in Sanfilippo type B: Case series of Brazilian patients.

Mucopolysaccharidosis type IIIB (MPS IIIB) is caused by deficiency of alpha-N-acetylglucosaminidase, leading to storage of heparan sulphate. The disease is characterized by intellectual disability and hyperactivity, among other neurological and somatic features. Here we studied retrospective data from a total of 19 MPS IIIB patients from Brazil, aiming to evaluate disease progression. Mean age at diagnosis was 7.2 years. Speech delay was one of the first symptoms to be identified, around 2-3 years of age. Behavioral alterations include hyperactivity and aggressiveness, starting around age four. By the end of the first decade, patients lost acquired abilities such as speech and ability to walk. Furthermore, as disease progresses, respiratory, cardiovascular and joint abnormalities were found in more than 50% of the patients, along with organomegaly. Most common cause of death was respiratory problems. The disease progression was characterized in multiple systems, and hopefully these data will help the design of appropriate clinical trials and clinical management guidelines.

Semiautomated approach focused on new genomic information results in time and effort-efficient reannotation of negative exome data.

Most rare disease patients (75-50%) undergoing genomic sequencing remain unsolved, often due to lack of information about variants identified. Data review over time can leverage novel information regarding disease-causing variants and genes, increasing this diagnostic yield. However, time and resource constraints have limited reanalysis of genetic data in clinical laboratories setting. We developed RENEW, (REannotation of NEgative WES/WGS) an automated reannotation procedure that uses relevant new information in on-line genomic databases to enable rapid review of genomic findings. We tested RENEW in an unselected cohort of 1066 undiagnosed cases with a broad spectrum of phenotypes from the Mayo Clinic Center for Individualized Medicine using new information in ClinVar, HGMD and OMIM between the date of previous analysis/testing and April of 2022. 5741 variants prioritized by RENEW were rapidly reviewed by variant interpretation specialists. Mean analysis time was approximately 20 s per variant (32 h total time). Reviewed cases were classified as: 879 (93.0%) undiagnosed, 63 (6.6%) putatively diagnosed, and 4 (0.4%) definitively diagnosed. New strategies are needed to enable efficient review of genomic findings in unsolved cases. We report on a fast and practical approach to address this need and improve overall diagnostic success in patient testing through a recurrent reannotation process.

GBA1 variants in Brazilian Gaucher disease patients.

Gaucher disease (GD) is an autosomal recessive lysosomal disorder caused by pathogenic variants in GBA1 which result in the deficient activity of glucocerebrosidase (GCase). There are few data on the genetic characterization of Brazilian GD patients. This study aimed at characterizing the genotype of 72 unrelated Brazilian GD patients (type I = 63, type II = 4, type III = 5; male = 31). Forty patients were from South Brazil (SB), and 32 were from other regions of Brazil (Others). The exons and exon/intron junctions of GBA1 were analyzed by Sanger sequencing in 8 patients, or by massive parallel sequencing followed by Sanger of exons 9 and 10 in 64 patients. In total, 31 pathogenic variants were identified. The most frequent allele found was N370S (p.(Asn409Ser)) (41.0%), and the most frequent genotype was N370S/RecNciI p.[Asn409Ser];[Leu483Pro;Ala495Pro;Val499=](23.6%). Three variants (N370S - in exon 9, and RecNciI and L444P (p.(Leu483Pro), in exon 10) correspond to 76.3% of total alleles in SB and 59.4% in Others. Two novel variants were described: c.326del(p.(Gln109Argfs*9)) and c.690G>A (p.(?)). Although sequencing all the exons of GBA1 is the gold-standard method for the genetic analysis of GD patients, a step analysis can be proposed for Brazilian patients, starting with analysis of exons 9 and 10. The N370S allele is the most frequently associated with GD in Brazil.

Diagnostic yield of multi-gene panel for muscular dystrophies and other hereditary myopathies.

Genetic testing is being considered the first-step in the investigation of hereditary myopathies. However, the performance of the different testing approaches is little known. The aims of the present study were to evaluate the diagnostic yield of a next-generation sequencing panel comprising 39 genes as the first-tier test for genetic myopathies diagnosis and to characterize clinical and molecular findings of families from southern Brazil. Fifty-one consecutive index cases with clinical suspicion of genetic myopathies were recruited from October 2014 to March 2018 in a cross-sectional study. The overall diagnostic yield of the next-generation sequencing panel was 52.9%, increasing to 60.8% when including cases with candidate variants. Multi-gene panel solved the diagnosis of 12/25 (48%) probands with limb-girdle muscular dystrophies, of 7/14 (50%) with congenital muscular diseases, and of 7/10 (70%) with muscular dystrophy with prominent joint contractures. The most frequent diagnosis for limb-girdle muscular dystrophies were LGMD2A/LGMD-R1-calpain3-related and LGMD2B/LGMD-R2-dysferlin-related; for congenital muscular diseases, RYR1-related-disorders; and for muscular dystrophy with prominent joint contractures, Emery-Dreifuss-muscular-dystrophy-type-1 and COL6A1-related-disorders. In summary, the customized next-generation sequencing panel when applied in the initial investigation of genetic myopathies results in high diagnostic yield, likely reducing patient's diagnostic odyssey and providing important information for genetic counseling and participation in disease-specific clinical trials.

Efficacy and Safety of Taliglucerase Alfa for the Treatment of Gaucher Disease: A 9-Year Experience

Abstract Gaucher disease (GD) is one of the most common lysosomal disorders, occurring in approximately 1 in 40,000 live births worldwide. Since 2014 enzyme replacement therapy (ERT) with taliglucerase alfa has been the treatment of choice for adult patients with GD in Brazil. The aim of this study was to evaluate the long-term efficacy and safety of taliglucerase alfa in a cohort of Brazilian patients treated at a referral center for inborn errors of metabolism. All patients who received at least one infusion of the enzyme at the study center were considered eligible to participate. Patients were followed for adverse reactions and events throughout the study period. Platelets, hemoglobin, chitotriosidase activity, bone marrow burden (BMB) score, bone mineral density, and the severity score index (SSI) were analyzed. For patients who were switched to taliglucerase alfa from imiglucerase, the same variables were compared before and after the switch. At 9-year follow-up, all parameters of interest had remained stable or improved. The overall rate of adverse events was lower than in other studies that evaluated long-term ERT with taliglucerase, and no serious adverse events were considered related to treatment. Based on our findings, ERT with taliglucerase alfa is an effective and safe approach for treatment of patients with GD.

Histomorphometric analysis of liver biopsies of treated patients with Gaucher disease type 1.

Gaucher disease (GD) is an autosomal recessive lysosomal disorder caused by a disturbance in the metabolism of glucocerebroside in the macrophages. Most of its manifestations - hepatosplenomegaly, anemia, thrombocytopenia, and bone pain - are amenable to a macrophage-target therapy such as enzyme replacement. However, there is increasing evidence that abnormalities of the liver persist despite the specific GD treatment. In this work, we adapted histomorphometry techniques to the study of hepatocytes in GD using liver tissue of treated patients, developing the first morphometrical method for canalicular quantification in immunohistochemistry-stained liver biopsies, and exploring histomorphometric characteristics of GD. This is the first histomorphometric technique developed for canalicular analysis on histological liver biopsy samples.

Histomorphometric analysis of liver biopsies of treated patients with Gaucher disease type 1

Gaucher disease (GD) is an autosomal recessive lysosomal disorder caused by a disturbance in the metabolism of glucocerebroside in the macrophages. Most of its manifestations - hepatosplenomegaly, anemia, thrombocytopenia, and bone pain - are amenable to a macrophage-target therapy such as enzyme replacement. However, there is increasing evidence that abnormalities of the liver persist despite the specific GD treatment. In this work, we adapted histomorphometry techniques to the study of hepatocytes in GD using liver tissue of treated patients, developing the first morphometrical method for canalicular quantification in immunohistochemistry-stained liver biopsies, and exploring histomorphometric characteristics of GD. This is the first histomorphometric technique developed for canalicular analysis on histological liver biopsy samples.

Transferrin isoelectric focusing for the investigation of congenital disorders of glycosylation: analysis of a ten-year experience in a Brazilian center / Isoeletrofocalização da transferrina para investigação das doenças congênitasda glicosilação: análise de dez anos de experiência de um centro brasileiro

Abstract Objectives: To characterize cases of suspected congenital disorders of glycosylation (CDG) investigated in a laboratory in southern Brazil using the transferrin isoelectric focusing TfIEF test from 2008 to 2017. Method: Observational, cross-sectional, retrospective study. The laboratory records of 1,546 individuals (median age = 36 months, 25-75 IQR = 10-108; males = 810) submitted to the TfIEF test during the period were reviewed. Results: Fifty-one individuals (3%) had an altered TfIEF pattern (5 ± 2.8 cases/year; median age = 24 months, 25-75 IQR = 11-57 months; males = 27, 53%). For 14 of them, data on diagnosis conclusion were available (classic galactosemia = 4; hereditary fructose intolerance = 4; peroxisomal diseases = 2; PMM2-CDG = 2; MPDU1-CDG = 1; SLC35A2-CDG = 1).Comparing the cases with the normal and altered TfIEF patterns, there was a higher prevalence of altered cases in the age group from 11 months to 3 years. There was an increase in the likelihood of change in TfIEF, especially in the presence of inverted nipples or liver disease. Conclusions: The data suggest that the investigation of a case with suspected CDG is a complex problem, being aggravated by the existence of other IEMs (inborn errors of metabolism) associated with altered TfIEF pattern and lack of access to confirmatory tests. The presence of inverted nipples and liver disease, especially in individuals aged 11 months to 3 years, should suggest the need for TfIEF investigation.

Resumo Objetivos: Caracterizar os casos com suspeita de CDG investigados em laboratório do sul do Brasil pelo exame de IEFTF de 2008 a 2017. Metodologia: Estudo observacional, transversal, retrospectivo. Foram revisadas as fichas laboratoriais de 1.546 indivíduos (mediana de idade = 36 meses, IQ 25-75 = 10-108; sexo masculino = 810) que fizeram o exame de IEFTF no período. Resultados: Cinquenta e um indivíduos (3%) apresentaram padrão alterado na IEFTF (5 ± 2,8 casos/ano; mediana de idade = 24 meses, IQ 25-75 = 11-57 meses; sexo masculino = 27, 53%). Para 14 deles, estavam disponíveis dados sobre a conclusão do diagnóstico (galactosemia clássica = 4; intolerância hereditária à frutose = 4; doenças peroxissomais = 2; PMM2-CDG = 2; MPDU1-CDG = 1; SLC35A2-CDG = 1). Comparando os casos com padrão normal e alterado na IEFTF, houve maior prevalência de casos alterados na faixa etária de 11 meses a 3 anos. Verificou-se um aumento na probabilidade de alteração na IEFTF principalmente na presença de mamilos invertidos ou de hepatopatia. Conclusões: Os nossos dados sugerem que a investigação de um caso com suspeita de CDG é complexa, é agravada pela existência de outros EIM associados a padrão alterado na IEFTF e pela falta de acesso a exames confirmatórios. A presença principalmente de mamilos invertidos e de hepatopatia em indivíduos na faixa etária de 11 meses a 3 anos deve sugerir a necessidade de investigação por IEFTF.

Bosch-Boonstra-Schaaf optic atrophy syndrome (BBSOAS) initially diagnosed as ALG6-CDG: Functional evidence for benignity of the ALG6 c.391T>C (p.Tyr131His) variant and further expanding the BBSOAS phenotype.

Bosch-Boonstra-Schaaf optic atrophy syndrome (BBSOAS) is a recently described autosomal dominant syndrome of developmental delay, cortical vision loss with optic nerve atrophy, epilepsy, and autism spectrum disorder. Due to its many overlapping features with congenital disorders of glycosylation (CDG), the differential diagnosis between these disorders may be difficult and relies on molecular genetic testing. We report on a 31-year-old female initially diagnosed with ALG6-CDG based on glycosylation abnormalities on transferrin isoelectrofocusing and targeted genetic testing, and later diagnosed with BBSOAS by whole-exome sequencing (WES). Functional studies on cultured fibroblasts including Western blotting and RT-qPCR, as well as mass spectrometry of glycosylated transferrin and MALDI-TOF glycan analysis in serum, demonstrated normal glycosylation in this patient. In this report, we extend the phenotype of BBSOAS with ataxia and protein-losing enteropathy. This case is illustrative of the utility of whole exome sequencing in the diagnostic odyssey, and the potential pitfalls of relying on focused genetic testing results for diagnosis of conditions with complex overlapping phenotypes.

Liver involvement in patients with Gaucher disease types I and III.

BACKGROUND & AIMS: Gaucher disease (GD) is a multisystemic disease. Liver involvement in GD is not well characterised and ranges from hepatomegaly to cirrhosis and hepatocellular carcinoma. We aim to describe, and assess the effect of treatment, on the hepatic phenotype of a cohort of patients with GD types I and II. METHODS: Retrospective study based on the review of the medical files of the Gaucher Reference Centre of the Hospital de Clínicas de Porto Alegre, Brazil. Data from all GD types I and III patients seen at the centre since 2003 were analysed. Variables were compared as pre- ("baseline") and post-treatment ("follow-up"). RESULTS: Forty-two patients (types I: 39, III: 3; female: 22; median age: 35 y; enzyme replacement therapy: 37; substrate reduction therapy: 2; non-treated: 3; median time on treatment-MTT: 124 months) were included. Liver enzyme abnormalities, hepatomegaly, and steatosis at baseline were seen in 19/28 (68%), 28/42 (67%), and 3/38 patients (8%), respectively; at follow-up, 21/38 (55%), 15/38 (39%) and 15/38 (39%). MRI iron quantification showed overload in 7/8 patients (treated: 7; MTT: 55 months), being severe in 2/7 (treated: 2/2; MTT: 44.5 months). Eight patients had liver biopsy (treated: 6; MTT: 58 months), with fibrosis in 3 (treated: 1; time on treatment: 108 months) and steatohepatitis in 2 (treated: 2; time on treatment: 69 and 185 months). One patient developed hepatocellular carcinoma. CONCLUSIONS: GD is a heterogeneous disease that causes different patterns of liver damage even during treatment. Although treatment improves the hepatocellular damage, it is associated with an increased rate of steatosis. This study highlights the importance of a follow-up of liver integrity in these patients.

Transferrin isoelectric focusing for the investigation of congenital disorders of glycosylation: analysis of a ten-year experience in a Brazilian center.

OBJECTIVES: To characterize cases of suspected congenital disorders of glycosylation (CDG) investigated in a laboratory in southern Brazil using the transferrin isoelectric focusing TfIEF test from 2008 to 2017. METHOD: Observational, cross-sectional, retrospective study. The laboratory records of 1,546 individuals (median age=36 months, 25-75 IQR=10-108; males=810) submitted to the TfIEF test during the period were reviewed. RESULTS: Fifty-one individuals (3%) had an altered TfIEF pattern (5±2.8 cases/year; median age=24 months, 25-75 IQR=11-57 months; males=27, 53%). For 14 of them, data on diagnosis conclusion were available (classic galactosemia=4; hereditary fructose intolerance=4; peroxisomal diseases=2; PMM2-CDG=2; MPDU1-CDG=1; SLC35A2-CDG=1).Comparing the cases with the normal and altered TfIEF patterns, there was a higher prevalence of altered cases in the age group from 11 months to 3 years. There was an increase in the likelihood of change in TfIEF, especially in the presence of inverted nipples or liver disease. CONCLUSIONS: The data suggest that the investigation of a case with suspected CDG is a complex problem, being aggravated by the existence of other IEMs (inborn errors of metabolism) associated with altered TfIEF pattern and lack of access to confirmatory tests. The presence of inverted nipples and liver disease, especially in individuals aged 11 months to 3 years, should suggest the need for TfIEF investigation.

Rare GBA1 genotype associated with severe bone disease in Gaucher disease type 1.

INTRODUCTION: Gaucher disease (GD) type 1 is a lysosomal disease characterised by hepatosplenomegaly, anemia, thrombocytopenia, bone changes, and bone marrow infiltration. The disease is caused by biallelic pathogenic variants in GBA1 which codes for glucocerebrosidase, an enzyme involved in the catabolic pathway of complex lipids. AIMS: To report on the case of two sisters with GD type 1 who bear a genotype never reported in the literature. CASE REPORT: Patient 1 is a 47-year-old female diagnosed at 42 years of age with chronic lumbar pain, mild splenomegaly, slightly reduced platelets and normal hemoglobin values, severe Bone Marrow Burden (BMB) score, high chitotriosidase activity, and low glucocerebrosidase. Patient 2 is a 50-year-old female, sister of patient 1, who was diagnosed after familial screening. At 45 years of age, she had osteonecrosis of the left femur and a total hysterectomy because of uncontrollable bleeding. At first evaluation, she had bone pain with a high BMB score, mild splenomegaly, normal hemoglobin, normal platelets count, elevated chitotriosidase activity, and low glucocerebrosidase activity. Both patients were found to be compound heterozygotes for the p.Glu388Lys and the p.Ser405Asn variants in GBA1. CONCLUSIONS: This is the first family with GD and this combination of variants which causes a phenotype remarkable for severe bone disease with no or mild hematological manifestations.

A systematic review and evidence-based guideline for diagnosis and treatment of Menkes disease.

Menkes disease is a rare X-linked neurodegenerative disorder caused by defect in copper metabolism. Parenteral copper supplementation has been used as a potential disease-modifying treatment of Menkes disease for decades. However, recent evidence suggests its efficacy only when treatment is started within days after birth, which also has important implications related to the techniques that enable early diagnosis. We aim at proposing a guideline for prenatal and neonatal diagnosis and for disease-modifying treatment of Menkes disease, guided by a systematic review of the literature, and built in conjunction with medical experts, methodologists and patient representatives. Thirteen articles were used for our recommendations that were based on GRADE system. Reviewed evidence suggests that prenatal genetic diagnosis in families with previous diagnosis of Menkes disease is feasible; analysis of plasma catecholamine levels is accurate for neonatal diagnosis of Menkes disease; treatment with copper-histidine is effective to increase survival and reduce neurologic burden of the disease if initiated in the neonatal period; and, treatment indication should not be guided by patient's genotype. In conclusion, our guideline can contribute to standardize some aspects of the clinical care of patients with Menkes disease, especially reducing disease burden and mortality and providers' and families' anxiety.

Use of a multiplex ligation-dependent probe amplification method for the detection of deletions/duplications in the GBA1 gene in Gaucher disease patients.

Gaucher disease (GD) is caused by the deficient activity of ß-glucocerebrosidase due to pathogenic mutations in the GBA1. This gene has a pseudogene (GBAP) with 96% of sequence homology. Recombination (Rec) events in the GBA1 seem to be facilitated by an increased degree of homology and proximity to the GBAP. The objectives of this study were to validate the P338-X1 GBA kit (MRC-Holland) for Multiplex Ligation-dependent Probe Amplification (MLPA) and to detect larger deletions/duplications present in GBA1 in GD patients from Brazil. Thirty-three unrelated Brazilian GD patients, previously genotyped by the Sanger method (both pathogenic alleles identified=29 patients, only one allele identified=3 patients, no pathogenic alleles identified=1 patient), were evaluated by the MLPA assay. MLPA was compatible with the previous results obtained by Sanger sequencing and identified an additional allele (a heterozygous deletion in intron 7 in one patient with only one mutation identified by Sanger). Our data suggest that, although larger deletions/duplications do not appear to be frequent in GD, the P338-X1 GBA kit for MLPA appears to be a good method for GBA1 analysis. Additional investigations should be performed in order to characterize the remaining four uncharacterized alleles of our sample.

Maple syrup urine disease: mechanisms and management.

Maple syrup urine disease (MSUD) is an inborn error of metabolism caused by defects in the branched-chain α-ketoacid dehydrogenase complex, which results in elevations of the branched-chain amino acids (BCAAs) in plasma, α-ketoacids in urine, and production of the pathognomonic disease marker, alloisoleucine. The disorder varies in severity and the clinical spectrum is quite broad with five recognized clinical variants that have no known association with genotype. The classic presentation occurs in the neonatal period with developmental delay, failure to thrive, feeding difficulties, and maple syrup odor in the cerumen and urine, and can lead to irreversible neurological complications, including stereotypical movements, metabolic decompensation, and death if left untreated. Treatment consists of dietary restriction of BCAAs and close metabolic monitoring. Clinical outcomes are generally good in patients where treatment is initiated early. Newborn screening for MSUD is now commonplace in the United States and is included on the Recommended Uniform Screening Panel (RUSP). We review this disorder including its presentation, screening and clinical diagnosis, treatment, and other relevant aspects pertaining to the care of patients.

Efficacy and safety of intravenous laronidase for mucopolysaccharidosis type I: A systematic review and meta-analysis.

OBJECTIVE: To evaluate the efficacy and safety of IV laronidase for MPS I. METHODS: A systematic literature review was performed by searching the ClinicalTrials.gov, MEDLINE/PubMed, EMBASE, LILACS, and Cochrane Library databases, limited to clinical trials published until December 31, 2016. The first inclusion criterion was being a randomized controlled trial (RCT). If < five RCTs were identified, open-label and nonrandomized trials, controlled or uncontrolled (quasi-experimental), including ≥ five patients, and evaluating relevant outcomes defined a priori, would also be included. For meta-analysis, primary inferences were based on random-effects models. Assessment of article quality was performed in accordance with the GRADE criteria. The Cochrane Risk of Bias tool was used to examine the risk of bias for RCTs. RESULTS: The selection phase retrieved 632 articles. During the first phase of selection, 158 had the abstract or full text read for assessment of eligibility, of which nine (two RCTs) were included for qualitative synthesis. Four papers were included in the meta-analysis, which was performed for the following outcomes: occurrence of treatment-emergent or infusion-related adverse events (65%; 95%CI 53, 76), mild in most cases; development of IgG antibodies to laronidase (88%; 95%CI 67, 100); apnea-hypopnea index (not significant-NS), urinary glycosaminoglycans (GAGs) [mean change -65.5 µg/mg creatinine (95%CI -68.8, -62.3)], liver size [mean change -31.03% (95%CI -36.1, -25.9)], left ventricular mass index (LVMI) [mean change -1.8 (95%CI -2.32, -0.25)], and distance covered in the 6-minute walk test (NS). Among the outcomes not included in meta-analysis, we found evidence for benefit of laronidase only on shoulder flexion. CONCLUSIONS: Our findings suggest that IV laronidase effectively reduces urinary GAGs excretion, hepatomegaly and LVMI, and can improve shoulder flexion in MPS I patients. Laronidase appears to be safe in the studied population.