A 10-year follow-up of high-dose ambroxol treatment combined with enzyme replacement therapy for neuropathic Gaucher disease

High-dose ambroxol therapy combined with ERT in patients with neuropathic Gaucher disease.

Clinical and genetic characteristics of three patients with congenital insensitivity to pain with anhidrosis: Case reports and a review of the literature

BACKGROUND

Congenital insensitivity to pain with anhidrosis (CIPA) is an extremely rare autosomal recessive disorder caused by loss-of-function mutations of the NTRK1 gene, affecting the autonomic and sensory nervous system. Clinical manifestation is varied and includes recurrent fever, pain insensitivity, anhidrosis, self-mutilating behavior, and intellectual disability.

METHODS

Clinical and genetic features were assessed in two males and one female with genetically confirmed CIPA using exome or genome sequencing.

RESULTS

CIPA symptoms including recurrent fever, pain insensitivity, and anhidrosis manifested at the age of 1 year (age range: 0.3-8 years). Two patients exhibited self-mutilation tendencies, intellectual disability, and developmental delay. Four NTRK1 (NM_002529.3) mutations, c.851-33T>A (p.?), c.2020G>T (p.Asp674Tyr), c.2303C>T (p.Pro768Leu), and c.574-156_850+1113del (exons 5-7 del) were identified. Two patients exhibited early onset and severe phenotype, being homozygous for c.851-33T>A (p.?) mutations and compound heterozygous for c.851-33T>A (p.?) and c.2020G>T (p.Asp674Tyr) mutation of NTRK1. The third patient with compound heterozygous mutations of c.2303C>T (p.Pro768Leu) and c.574-156_850+1113del (exons 5-7 del) displayed a late onset and milder clinical manifestation.

CONCLUSION

All three patients exhibited variable phenotypes and disease severity. This research enriches our understanding of clinical and genetic aspects of CIPA, highlighting variable phenotypes and disease severity.

Identification of a complex intrachromosomal inverted insertion in the long arm of chromosome 9 as a cause of tuberous sclerosis complex in a Korean family

BACKGROUND

Tuberous sclerosis complex (TSC) is an autosomal dominant multisystem disorder, caused by a loss-of-function of either TSC1 or TSC2 gene. However, in 10%-15% TSC patients there is no pathogenic variant identified in either TSC1 or TSC2 genes based on standard clinical testing.

METHODS

In this study, genome sequencing was performed for families with clinical diagnosis of TSC with negative results from TSC1 and TSC2 single-gene tests.

RESULTS

Herein, we report a family presenting a classical TSC phenotype with an unusual, complex structural variant involving the TSC1 gene: an intrachromosomal inverted insertion in the long arm of chromosome 9. We speculate that the inverted 9q33.3q34.13 region was inserted into the q31.2 region with the 3'-end of the breakpoint of the inversion being located within the TSC1 gene, resulting in premature termination of TSC1.

CONCLUSIONS

In this study, we demonstrate the utility of genome sequencing for the identification of complex chromosomal rearrangement. Because the breakpoints are located within the deep intronic/intergenic region, this copy-neutral variant was missed by the TSC1 and TSC2 single-gene tests and contributed to an unknown etiology. Together, this finding suggests that complex structural variants may be underestimated causes for the etiology of TSC.

Genetic heterogeneity of cardiomyopathy and its correlation with patient care

BACKGROUND

Cardiomyopathy, which is a genetically and phenotypically heterogeneous pathological condition, is associated with increased morbidity and mortality. Genetic diagnosis of cardiomyopathy enables accurate phenotypic classification and optimum patient management and counseling. This study investigated the genetic spectrum of cardiomyopathy and its correlation with the clinical course of the disease.

METHODS

The samples of 72 Korean patients with cardiomyopathy (43 males and 29 females) were subjected to whole-exome sequencing (WES). The familial information and clinical characteristics of the patients were reviewed and analyzed according to their genotypes.

RESULTS

Dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM), left ventricular non-compaction cardiomyopathy, and restrictive cardiomyopathy was detected in 41 (56.9%), 25 (34.7%), 4 (5.6%), and 2 (2.8%) patients, respectively. WES analysis revealed positive results in 37 (51.4%) patients. Subsequent familial testing identified ten additional familial cases. Among DCM cases, 19 (46.3%) patients exhibited positive results, with TTN variants being the most common alteration, followed by LMNA and MYH7 variants. Meanwhile, among HCM cases, 15 (60%) patients exhibited positive results with MYH7 variants being the most common alteration. In six patients with positive results, extracardiac surveillance was warranted based on disease information. The incidence of worse outcomes, such as mortality and life-threatening arrhythmic events, in patients with DCM harboring LMNA variants, was higher than that in patients with DCM harboring TTN or MYH7 variants.

CONCLUSIONS

Diverse genotypes were identified in a substantial proportion of patients with cardiomyopathy. Genetic diagnosis enables personalized disease surveillance and management.

Treatment Outcomes and Toxicity Profile of MRI-Guided Gated-Real Time Online Adaptive Stereotactic Body Radiotherapy to Patients with Pancreatic Tumors

PURPOSE/OBJECTIVE(S)

Stereotactic body radiation therapy (SBRT) to patients with inoperable pancreas cancer has shown promising outcomes. Dose escalation is challenging given the associated risks to nearby organs at risk and requires treatment plan adaptation and motion management. This study reports the treatment related adverse events and treatment outcomes of MRI-guided SBRT utilizing gated-real time online adaptive radiotherapy to patients with pancreatic tumors.

MATERIALS/METHODS

This is a single institution retrospective IRB approved study and included patients with pancreatic tumors who were treated with MRI-guided SBRT utilizing gated-real time online adaptive radiotherapy, consecutively between 2019 and 2022. All patients were treated with 0.35T MRI linear accelerator. All patients' charts and radiation plans were reviewed for this study.

RESULTS

The study included 25 patients treated consecutively to 125 radiation fractions with MRI-guided SBRT. The study included 15 females and 10 males, 19 white, 2 Asians, 1 Latin American and 2 African Americans. The median age was 74, and all patients had pancreatic adenocarcinoma (92%) except two patients who had biopsy proven renal cell carcinoma metastatic to the pancreas without evidence of disease elsewhere. Most patients (68%) received chemotherapy (FOLFIRINOX or Gemcitabine / Protein-bound paclitaxel) prior to SBRT. The median dose to gross target volume (GTV) was 50 Gy, and to planning target volume (PTV) was 35 Gy. All patients were treated in 5 radiation fractions. Thirteen patients (52%) received elective nodal irradiation (ENI). All patients had at least a single real-time online adaptive replanning (median 3 fractions, range 1-5 fractions). All treatment fractions were gated (100%) with MRI guidance. The 1-, 2-, & 3- year local-regional control (LRC) were 81%, 57%, & 57% respectively (Median 16 months). The 1-, 2-, & 3- year Distant Control (DC) were 81%, 74%, & 56% respectively (Median 14 months). The 1-, 2-, 3-year overall survival (OS) were 77%, 35%, & 24% (Median 21 months). Planning Target Volume (PTV) dose ≥40Gy was significantly associated with improved local-regional control (p = 0.02). Gross Target Volume (GTV) dose <50Gy was significantly associated with lower DC (p = 0.03). ENI showed a trend towards improved local-regional control but was not statistically significant (p = 0.1). None of the patients experienced ≥ grade 3 toxicities. Most common adverse event were grades 1 or 2 fatigue (24%), nausea (16%), and abdominal discomfort (12%).

CONCLUSION

In this cohort, MRI-guided SBRT utilizing gated-real time online adaptive radiotherapy was a safe and effective approach for patients with pancreatic tumors who are not surgical candidates. In this study, dose escalation was significantly associated with improved local-regional (PTV ≥40 Gy) and distant control (GTV ≥50Gy). None of the patients experienced grade ≥3 radiation induced adverse events.

Case report: a premature infant with severe intrauterine growth restriction, adrenal insufficiency, and inflammatory diarrhea: a genetically confirmed case of MIRAGE syndrome

Introduction

MIRAGE syndrome is a rare disease characterized by myelodysplasia, infection, growth restriction, adrenal hypoplasia, genital phenotypes, and enteropathy. Herein, we report the case of a girl with MIRAGE syndrome who presented with adrenal insufficiency and chronic diarrhea.

Case presentation

The patient was born at 29 + 6 weeks of gestational age with a birth weight of 656 g (<3p). Her height and head circumference were also <3p. At birth, she presented with respiratory distress, meconium staining, and pneumomediastinum, which were managed with high-frequency ventilation and empirical antibiotics. Physical examination showed generalized hyperpigmentation and normal female genitalia. A few days after birth, polyuria and hypotension developed, and laboratory findings revealed hypoglycemia, hyponatremia, and hyperkalemia. Plasma adrenocorticotropic hormone levels were elevated with low serum cortisol levels and high plasma renin activity, which were suggestive of adrenal insufficiency. Hydrocortisone and fludrocortisone were introduced and maintained, and hyperpigmentation attenuated with time. Both kidneys looked dysplastic, and adrenal glands could not be traced on abdominal ultrasound. From the early days of life, thrombocytopenia and anemia were detected, but not to life-threatening level and slowly recovered up to the normal range. Despite aggressive nutritional support, weight gain and growth spurt were severely retarded during the hospital stay. Additionally, after introducing enteral feeding, she experienced severe diarrhea and subsequent perineal skin rashes and ulcerations. Fecal calprotectin level was highly elevated; however, a small bowel biopsy resulted in non-specific submucosal congestion. The patient was diagnosed with MIRAGE syndrome with SAMD9 gene mutation. She was discharged with tube feeding and elemental formula feeding continued, but chronic diarrhea persisted. By the time of the last follow-up at 15 months of corrected age, she was fortunately not subjected to severe invasive infection and myelodysplastic syndrome. However, she was dependent on tube feeding and demonstrated a severe developmental delay equivalent to approximately 5-6 months of age.

Conclusion

The early diagnosis of adrenal crisis and hormone replacement therapy can save the life of -patients with MIRAGE syndrome; however, chronic intractable diarrhea and growth and developmental delay continue to impede the patient's well-being.

Selection of iPSCs without mtDNA deletion for autologous cell therapy in a patient with Pearson syndrome

Screening for genetic defects in the cells should be examined for clinical application. The Pearson syndrome (PS) patient harbored nuclear mutations in the POLG and SSBP1 genes, which could induce systemic large-scale mitochondrial genome (mtDNA) deletion. We investigated iPSCs with mtDNA deletions in PS patient and whether deletion levels could be maintained during differentiation. The iPSC clones derived from skin fibroblasts (9% deletion) and blood mononuclear cells (24% deletion) were measured for mtDNA deletion levels. Of the 13 skin-derived iPSC clones, only 3 were found to be free of mtDNA deletions, whereas all blood-derived iPSC clones were found to be free of deletions. The iPSC clones with (27%) and without mtDNA deletion (0%) were selected and performed in vitro and in vivo differentiation, such as embryonic body (EB) and teratoma formation. After differentiation, the level of deletion was retained or increased in EBs (24%) or teratoma (45%) from deletion iPSC clone, while, the absence of deletions showed in all EBs and teratomas from deletion-free iPSC clones. These results demonstrated that non-deletion in iPSCs was maintained during in vitro and in vivo differentiation, even in the presence of nuclear mutations, suggesting that deletion-free iPSC clones could be candidates for autologous cell therapy in patients. [BMB Reports 2023; 56(8): 463-468].

Context-aware deep network for coronary artery stenosis classification in coronary CT angiography

Automatic coronary artery stenosis grading plays an important role in the diagnosis of coronary artery disease. Due to the difficulty of learning the informative features from varying grades of stenosis, it is still a challenging task to identify coronary artery stenosis from coronary CT angiography (CCTA). In this paper, we propose a context-aware deep network (CADN) for coronary artery stenosis classification. The proposed method integrates 3D CNN with Transformer to improve the feature representation of coronary artery stenosis in CCTA. We evaluate the proposed method on a multicenter dataset (APOLLO study with NCT05509010). Experimental results show that our proposed method can achieve the accuracy of 0.84, 0.83, and 0.86 for stenosis diagnosis on the lesion, artery, and patient levels, respectively.

Genetic diagnosis of kidney disease by whole exome sequencing and its clinical application

The genetic spectrum of genetic kidney diseases (GKD) and the application of genetic diagnoses to patient care were assessed by whole exome sequencing (WES) of the DNA of 172 pediatric or adult patients with various kidney diseases. WES diagnosed genetic diseases in 63 (36.6%) patients. The diagnostic yields in patients with glomerulopathy were 33.8% (25/74 pts) due to variants in 10 genes, 58.8% (20/34) in patients with tubulointerstitial disease due to variants in 18 genes, 33.3% (15/45) in patients with cystic disease/ciliopathy due to variants in 10 genes, 18.2% (2/11) in patients with congenital anomalies of the kidneys and urinary tract (CAKUT) due to variants in two genes, and 12.5% (1/8) in patients with end stage kidney disease (ESKD). The diagnosis rate was high in patients aged <1-6 years (46-50.0%), and low in patients aged ≥40 years (9.1%). Renal phenotype was reclassified in 10 (15.9%) of 63 patients and clinical management altered in 10 (15.9%) of 63 patients after genetic diagnosis. In conclusion, these findings demonstrated the diagnostic utility of WES and its effective clinical application in patients, with various kinds of kidney diseases, across the different age groups.

Fasudil alleviates the vascular endothelial dysfunction and several phenotypes of Fabry disease

Fabry disease (FD), a lysosomal storage disorder, is caused by defective α-galactosidase (GLA) activity, which results in the accumulation of globotriaosylceramide (Gb3) in endothelial cells and leads to life-threatening complications such as left ventricular hypertrophy (LVH), renal failure, and stroke. Enzyme replacement therapy (ERT) results in Gb3 clearance; however, because of a short half-life in the body and the high immunogenicity of FD patients, ERT has a limited therapeutic effect, particularly in patients with late-onset disease or progressive complications. Because vascular endothelial cells (VECs) derived from FD-induced pluripotent stem cells display increased thrombospondin-1 (TSP1) expression and enhanced SMAD2 signaling, we screened for chemical compounds that could downregulate TSP1 and SMAD2 signaling. Fasudil reduced the levels of p-SMAD2 and TSP1 in FD-VECs and increased the expression of angiogenic factors. Furthermore, fasudil downregulated the endothelial-to-mesenchymal transition (EndMT) and mitochondrial function of FD-VECs. Oral administration of fasudil to FD mice alleviated several FD phenotypes, including LVH, renal fibrosis, anhidrosis, and heat insensitivity. Our findings demonstrate that fasudil is a novel candidate for FD therapy.

Therapeutic gene correction for Lesch-Nyhan syndrome using CRISPR-mediated base and prime editing

Lesch-Nyhan syndrome (LNS) is inherited as an X-linked recessive genetic disorder caused by mutations in hypoxanthine-guanine phosphoribosyl transferase 1 (HPRT1). Patients with LNS show various clinical phenotypes, including hyperuricemia, gout, devastating behavioral abnormality, intellectual disability, and self-harm. Although uric acid overproduction can be modulated with the xanthine oxidase inhibitor allopurinol, there exists no treatment for behavioral and neurological manifestations of LNS. In the current study, CRISPR-mediated base editors (BEs) and prime editors (PEs) were utilized to generate LNS-associated disease models and correct the disease models for therapeutic approach. Cytosine BEs (CBEs) were used to induce c.430C>T and c.508C>T mutations in HAP1 cells, and then adenine BEs (ABEs) were used to correct these mutations without DNA cleavage. PEs induced a c.333_334ins(A) mutation, identified in a Korean patient with LNS, in HAP1 cells, which was corrected in turn by PEs. Furthermore, improved PEs corrected the same mutation in LNS patient-derived fibroblasts by up to 14% without any unwanted mutations. These results suggest that CRISPR-mediated BEs and PEs would be suggested as a potential therapeutic strategy of this extremely rare, devastating genetic disease.

MOGS-CDG: Quantitative analysis of the diagnostic Glc3 Man tetrasaccharide and clinical spectrum of six new cases

Congenital disorders of glycosylation (CDG) are a clinically and biochemically heterogeneous subgroup of inherited metabolic disorders. Most CDG with abnormal N-glycosylation can be detected by transferrin screening, however, MOGS-CDG escapes this routine screening. Combined with the clinical heterogeneity of reported cases, diagnosing MOGS-CDG can be challenging. Here, we clinically characterize ten MOGS-CDG cases including six previously unreported individuals, showing a phenotype characterized by dysmorphic features, global developmental delay, muscular hypotonia, and seizures in all patients and in a minority vision problems and hypogammaglobulinemia. Glycomics confirmed accumulation of a Glc₃ Man₇ GlcNAc₂ glycan in plasma. For quantification of the diagnostic Glcα1-3Glcα1-3Glcα1-2Man tetrasaccharide in urine, we developed and validated a liquid chromatography-mass spectrometry method of 2-aminobenzoic acid (2AA) labeled urinary glycans. As an internal standard, isotopically labeled ¹³ C₆ -2AA Glc₃ Man was used, while labeling efficiency was controlled by use of ¹² C₆ -2AA and ¹³ C₆ -2AA labeled laminaritetraose. Recovery, linearity, intra- and interassay coefficients of variability of these labeled compounds were determined. Furthermore, Glc₃ Man was specifically identified by retention time matching against authentic MOGS-CDG urine and compared with Pompe urine. Glc₃ Man was increased in all six analyzed cases, ranging from 34.1 to 618.0 μmol/mmol creatinine (reference <5 μmol). In short, MOGS-CDG has a broad manifestation of symptoms but can be diagnosed with the use of a quantitative method for analysis of urinary Glc₃ Man excretion.

Pediatric hepatocellular carcinoma associated with Niemann-Pick disease type C: Case report and literature review

Niemann-Pick disease type C (NPC) is a rare, autosomal recessive, lysosomal storage disease, resulting from mutations in the cholesterol trafficking proteins NPC1 or NPC2, which is characterized by progressive neurodegeneration and hepatic dysfunction. The hepatic involvement in NPC is usually neonatal cholestasis and hepatosplenomegaly. Only a few cases of severe hepatic complications were reported including acute liver failure, cirrhosis, and hepatocellular carcinoma (HCC). We described the case of a 6-year-old male with NPC with HCC. He had a history of neonatal cholestasis and motor delay. At the age of 6 months, he was diagnosed with NPC, which was confirmed by the detection of a compound heterozygous NPC1 mutation (p.C113Y/p.A927V). He presented recurrent hypoglycemia and abdominal distension. An ultrasound, computed tomography scan, and biopsy revealed that he had a stage IV HCC with pulmonary metastasis. With the literature review and this case, HCC can be a rare fatal comorbid condition in patients with NPC, particularly infantile-onset, male patients with a relatively long disease history, necessitating appropriate HCC surveillance.

KBG syndrome: Clinical features and molecular findings in seven unrelated Korean families with a review of the literature

BACKGROUND

KBG syndrome is a rare genetic disorder involving macrodontia of the upper central incisors, craniofacial, skeletal, and neurologic symptoms, caused either by a heterozygous variant in ANKRD11 or deletion of 16q24.3, including ANKRD11. Diagnostic criteria were proposed in 2007 based on 50 cases, but KBG syndrome remains underdiagnosed.

METHODS

Whole exome sequencing (WES) and array comparative genomic hybridization (array CGH) were conducted for genetic analysis and patient phenotypes were characterized based on medical records.

RESULTS

Eight patients from seven unrelated families were confirmed with KBG syndrome. All patients (8/8, 100%) had some degree of craniofacial dysmorphism and developmental delay or intellectual disabilities. Triangular face, synophrys, anteverted nostril, prominent ears, long philtrum, and tented upper lip, which are typical facial dysmorphism findings in patients with KBG syndrome, were uniformly identified in the eight patients participating in this study, with co-occurrence rates of 4/8 (50%), 4/8 (50%), 4/8 (50%), 4/8 (50%), 5/8 (62.5%), and 5/8 (62.5%), respectively. Various clinical manifestations not included in the diagnostic criteria were observed. Six patients had point mutations in ANKRD11, one had an exonic deletion of ANKRD11, and one had a 16q24.3 microdeletion. According to the ACMG guidelines, all mutations were classified as pathogenic. The c.2454dup (p.Asn819fs*1) mutation in Pt 4 was reported previously. The remaining variants (c.397 + 1G>A, c.226 + 1G>A, c.2647del (p.Glu883Argfs*94), and c.4093C>T (p.Arg1365Ter)) were novel.

CONCLUSION

The clinical and molecular features of eight patients from seven unrelated Korean families with KBG syndrome described here will assist physicians in understanding this rare genetic condition.

Bi-allelic loss-of-function variants in TMEM147 cause moderate to profound intellectual disability with facial dysmorphism and pseudo-Pelger-Huët anomaly

The transmembrane protein TMEM147 has a dual function: first at the nuclear envelope, where it anchors lamin B receptor (LBR) to the inner membrane, and second at the endoplasmic reticulum (ER), where it facilitates the translation of nascent polypeptides within the ribosome-bound TMCO1 translocon complex. Through international data sharing, we identified 23 individuals from 15 unrelated families with bi-allelic TMEM147 loss-of-function variants, including splice-site, nonsense, frameshift, and missense variants. These affected children displayed congruent clinical features including coarse facies, developmental delay, intellectual disability, and behavioral problems. In silico structural analyses predicted disruptive consequences of the identified amino acid substitutions on translocon complex assembly and/or function, and in vitro analyses documented accelerated protein degradation via the autophagy-lysosomal-mediated pathway. Furthermore, TMEM147-deficient cells showed CKAP4 (CLIMP-63) and RTN4 (NOGO) upregulation with a concomitant reorientation of the ER, which was also witnessed in primary fibroblast cell culture. LBR mislocalization and nuclear segmentation was observed in primary fibroblast cells. Abnormal nuclear segmentation and chromatin compaction were also observed in approximately 20% of neutrophils, indicating the presence of a pseudo-Pelger-Huët anomaly. Finally, co-expression analysis revealed significant correlation with neurodevelopmental genes in the brain, further supporting a role of TMEM147 in neurodevelopment. Our findings provide clinical, genetic, and functional evidence that bi-allelic loss-of-function variants in TMEM147 cause syndromic intellectual disability due to ER-translocon and nuclear organization dysfunction.

Clinical and genetic analyses of patients with lateralized overgrowth

Background

The genetic features and treatment strategies of lateralized overgrowth have been elusive. We performed this study to analyze the genetic characteristics and treatment results of propranolol- or alpelisib-treated patients with lateralized overgrowth.

Methods

Fifteen patients with lateralized overgrowth were involved. Clinical characteristics and whole-body magnetic resonance imaging (WB-MRI) findings were evaluated. Targeted exome sequencing with a gene panel of affected tissue and peripheral white blood cells was performed. Propranolol was administered and treatment results were evaluated. The PIK3CA inhibitor alpelisib was prescribed via a managed access program.

Results

The identified mutations were PIK3CA (n = 7), KRAS (n = 2), PTEN (n = 1), MAP2K3 (n = 1), GNAQ (n = 1), TBC1D4 (n = 1), and TEK (n = 1). Propranolol was prescribed in 12 patients, and 7 experienced mild improvement of symptoms. Alpelisib was prescribed in two patients with a PIK3CA mutation, and the reduction of proliferated masses after 1 year of treatment was proved by WB-MRI.

Conclusions

Targeted exome sequencing identified various genetic features of lateralized overgrowth. Propranolol could be applied as an adjuvant therapy for reducing vascular symptoms, but a PIK3CA inhibitor would be the primary therapeutic strategy for PIK3CA-related overgrowth syndrome.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01362-1.

A phase II, multicenter, open-label trial to evaluate the safety and efficacy of ISU303 (Agalsidase beta) in patients with Fabry disease

BACKGROUND

Fabry disease (FD) is caused by a deficiency in the activity of the lysosomal enzyme, α-galactosidase A (α-Gal A), which leads to globotriaosylceramide (Gb3) deposition in multiple tissues. The current management of FD is enzyme replacement therapy (ERT). We report on the efficacy and safety of a new agalsidase beta, ISU303, in FD.

METHODS

Ten patients (7 males, 3 females) were enrolled and administered a 1 mg/kg dose of ISU303, every other week for 6 months. The primary endpoint was the normalization of plasma Gb3 level. The secondary endpoints were the changes from baseline in urine Gb3 and the plasma and urine lyso-globotriaosylsphingosine (lyso-Gb3) level. Echocardiography, renal function test, and pain-related quality of life were also assessed before and after administration. Safety evaluation was performed including vital signs, laboratory tests, electrocardiograms, antibody screening tests, and adverse events at each visit.

RESULTS

At 22 weeks of treatment, plasma and urine Gb3 level decreased by a mean of 4.01 ± 1.29 μg/mL (range 2.50-5.70) (P = .005) and 1.12 ± 1.98 μg/mg Cr. (range 0.04-5.65) (P = .017), respectively. However, no significant difference was observed in plasma and urine lyso-Gb3 levels. Echocardiography also was not changed. Renal function and pain-related quality of life showed improvements, but there was no clinical significance. No severe adverse events were observed. Only 1 patient developed an anti-drug antibody without neutralizing activity during the trial.

CONCLUSION

This study showed the efficacy and safety of ISU303. Treatment with ISU303 significantly resulted in plasma and urine Gb3 decrease in patients with FD. These results suggest that ISU303 is safe and effective and can alternative ERT for FD.

Evaluation of users' level of satisfaction for an artificial intelligence-based diagnostic program in pediatric rare genetic diseases

The artificial intelligence (AI)-based genetic diagnostic program has been applied to genome sequencing to facilitate the diagnostic process. The objective of the current study was to evaluate the experience and level of satisfaction of participants using an AI-based diagnostic program for rare pediatric genetic diseases. The patients with neurodevelopmental disorders or hearing impairments, their guardians, and their physicians from 16 tertiary general hospitals were enrolled. The study period was from April 2020 to March 2021. A survey was designed to assess their experience and level of satisfaction. A total of 30 physicians and 243 patients and guardians (199 neurodevelopmental disorders and 44 hearing impairments) completed the survey. DNA samples of the subjects were collected through buccal swabs or blood collection: 211 subjects (86.8%) through buccal swab and 29 subjects (11.9%) through blood collection. Average turnaround time for result receipt was 57.54 ± 32.42 days. For the sampling method, 193 patients and guardians (81.1%) and 28 physicians (93.3%) preferred buccal swab. The level of satisfaction of the 2 groups participating in the AI-based diagnostic program was 8.31 ± 1.71 out of 10 in the patient and guardian group and 8.42 ± 1.23 in the physician group. Clinicians, patients, and guardians are satisfied with the AI-based diagnostic program in general. With an increase in AI-based precision medicine solutions, the evaluation of the user's satisfaction with appropriate provision will help improve personal health care.

Phenotypic and Genetic Complexity in Pediatric Movement Disorders

The complex and evolving nature of clinical phenotypes have made genetically diagnosing pediatric patients with movement disorders difficult. Here, we describe this diverse complexity in the clinical and genetic features of a pediatric cohort examined by whole-exome sequencing (WES) and demonstrate the clinical benefit of WES as a diagnostic tool in a pediatric cohort. We evaluated 75 patients with diverse single or combined movement phenomenologies using WES. WES identified 42 variants in 37 genes (56.0%). The detection rate was highest in patients with dystonia (11/13, 84.6%), followed by ataxia (21/38, 55.3%), myoclonus (3/6, 50.0%), unspecified dyskinesia (1/4, 25.0%), tremor (1/1, 100%), respectively. Most genetically diagnosed patients (90.5%) were affected by other neurologic or systemic manifestations; congenital hypotonia (66.7%), and epilepsy (42.9%) were the most common phenotypes. The genetic diagnosis changed the clinical management for five patients (6.7%), including treatments targeting molecular abnormalities, and other systemic surveillance such as cancer screening. Early application of WES yields a high diagnostic rate in pediatric movement disorders, which can overcome the limitations of the traditional phenotype-driven strategies due to the diverse phenotypic and genetic complexity. Additionally, this early genetic diagnosis expands the patient’s clinical spectrum and provides an opportunity for tailored treatment.

Genotype-phenotype correlations and long-term efficacy of pamidronate therapy in patients with osteogenesis imperfecta

PURPOSE

Osteogenesis imperfecta (OI) is a rare bone fragility disorder caused by defects in type 1 collagen biosynthesis. This study investigated the genotype-phenotype correlations and the efficacy of pamidronate therapy in patients with OI in a single academic center.

METHODS

This study included 24 patients with OI. A clinical scoring system was used to evaluate disorder severity. COL1A1 and COL1A2 genes were analyzed in 13 patients using Sanger sequencing. Genotype-phenotype correlations and the efficacy of pamidronate therapy were analyzed through a retrospective medical chart review.

RESULTS

Of the 24 patients, 18 (75%) were classified as type I (12 with type Ia and 6 with type Ib), 2 as type III (8.4%), and 4 as type IV (16.7%). Type Ia patients showed relatively higher lumbar bone mineral density (BMD) standard deviation scores (SDS) and lower clinical scores than those with other types. Seven patients with qualitative mutations had lower lumbar BMD-SDS (P=0.015) and higher clinical scores (P=0.008) than 6 patients with quantitative mutations. The annual fracture frequency and lumbar BMD-SDS improved in patients with qualitative mutations after pamidronate treatment.

CONCLUSION

This study demonstrated that OI patients with qualitative mutations in COL1A1/2 had a more severe phenotype than those with quantitative mutations. Patients with qualitative mutations showed a significant reduction in fracture frequency and an increase in lumbar BMD-SDS after pamidronate treatment. Clinical score and genotype might be helpful for predicting phenotype and response to pamidronate therapy in OI patients.

Clinical and genetic features of four patients with Pearson syndrome: An observational study

Pearson syndrome (PS) is a multisystem mitochondrial cytopathy arising from deletions in mitochondrial DNA. Pearson syndrome is a sporadic disease that affects the hematopoietic system, pancreas, eyes, liver, and heart and the prognosis is poor. Causes of morbidity include metabolic crisis, bone marrow dysfunction, sepsis, and liver failure in early infancy or childhood. Early diagnosis may minimize complications, but suspicion of the disease is difficult and only mitochondrial DNA gene testing can identify mutations. There is no specific treatment for PS, which remains supportive care according to symptoms; however, hematopoietic stem cell transplantation may be considered in cases of bone marrow failure.We herein describe the clinical and genetic characteristics of four patients with PS. One patient presented with hypoglycemia, two developed pancytopenia, and the final patient had hypoglycemia and acute hepatitis as the primary manifestation. All patients had lactic acidosis. Additionally, all patients showed a variety of clinical features including coagulation disorder, pancreatic, adrenal, and renal tubular insufficiencies. Two patients with pancytopenia died in their early childhood. Our experience expands the phenotypic spectrum associated with PS and its clinical understanding.

Whole-body MRI evaluation in neurofibromatosis type 1 patients younger than 3 years old and the genetic contribution to disease progression

Background

Neurofibromatosis type 1 (NF1) is a common human genetic disease with age-dependent phenotype progression. The overview of clinical and radiological findings evaluated by whole-body magnetic resonance imaging (WBMRI) in NF1 patients < 3 years old assessed with a genetic contribution to disease progression is presented herein.

Methods

This study included 70 clinically or genetically diagnosed NF1 patients who received WBMRI before 3 years old. Clinical, genetic, and radiologic features were collected by retrospective chart review. In NF1⁺, widely spread diffuse cutaneous neurofibromas, developmental delay, autism, seizure, cardiac abnormalities, hearing defect, optic pathway glioma, severe plexiform neurofibromas (> 3 cm in diameter, disfigurement, accompanying pain, bony destruction, or located para-aortic area), brain tumors, nerve root tumors, malignant peripheral nerve sheath tumors, moyamoya disease, and bony dysplasia were included.

Results

The age at WBMRI was 1.6 ± 0.7 years old, and NF1 mutations were found in 66 patients (94.3%). Focal areas of signal intensity (FASI) were the most common WBMRI finding (66.1%), followed by optic pathway glioma (15.7%), spine dural ectasia (12.9%), and plexiform neurofibromas (10.0%). Plexiform neurofibromas and NF1⁺ were more prevalent in familial case (28.7% vs 5.7%, p = 0.030; 71.4% vs 30.2%, p = 0.011). Follow-up WBMRI was conducted in 42 patients (23 girls and 19 boys) after 1.21 ± 0.50 years. FASI and radiologic progression were more frequent in patients with mutations involving GTPase activating protein-related domain (77.8% vs 52.4%, p = 0.047; 46.2% vs 7.7%, p = 0.029).

Conclusions

WBMRI provides important information for the clinical care for young pediatric NF1 patients. As NF1 progresses in even these young patients, and is related to family history and the affected NF1 domains, serial evaluation with WBMRI should be assessed based on the clinical and genetic features for the patients’ best care.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-022-02174-3.

Efficacy and Safety of Selumetinib in Pediatric Patients With Neurofibromatosis Type 1: A Systematic Review and Meta-analysis

BACKGROUND AND OBJECTIVES

Although the recent approval of selumetinib is expected to transform the management of children with Neurofibromatosis type 1 (NF1), particularly those with symptomatic and inoperable PN, no systematic review has summarized their efficacy and safety based on the latest studies. This study was conducted to systematically evaluate the efficacy and safety of selumetinib in children with NF1 METHODS: Original articles reporting the efficacy and safety of selumetinib in patients with NF1 were identified in PubMed and EMBASE up to January 28, 2021. The pooled objective response rates (ORRs) and disease control rates (DCRs) were calculated using the DerSimonian-Laird method based on random-effects modeling. The pooled proportion of adverse events (AEs) was also calculated. The quality of the evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluation system.

RESULTS

Five studies involving 126 patients were included in our analysis. The studies had a very low to moderate quality of the evidence. The pooled ORR was 73.8% (95% CI: 57.3-85.5%), and the DCR was 92.5% (95% CI: 66.5-98.7%). The two most common AEs were diarrhea, which had a pooled rate of 63.8% (95% CI, 52.9-73.4%) and an increase in creatine kinase levels, which had a pooled rate of 63.3% (95% CI, 35.6-84.3%).

DISCUSSION

Our results indicate that selumetinib is an effective and safe treatment for pediatric patients with symptomatic, inoperable plexiform neurofibromas. Further larger-scale randomized controlled studies are needed to confirm the long-term outcome of patients treated with this drug.

Unfavorable clinical outcomes in patients with carbamoyl phosphate synthetase 1 deficiency

PURPOSE

Carbamoyl phosphate synthetase 1 (CPS1) deficiency affects the first step of urea cycle and is a severe form of urea cycle disorder (UCD). The severity of hyperammonemic encephalopathy determines the clinical course of UCDs. Here, we describe the genetic and clinical characteristics of CPS1 deficiency in Korea.

PATIENT AND METHODS

This study included seven patients with CPS1 deficiency genetically confirmed from January 1992 to September 2020. The peak ammonia level during the first crisis, the half time of peak ammonia level, the initial plasma amino acid levels, and neurological outcomes were compared between CPS1 deficiency and two common UCDs (i.e., 17 patients with argininosuccinate synthetase 1 deficiency and 24 patients with ornithine transcarbamylase deficiency).

RESULT

Eleven CPS1 mutations were identified, including 10 novel mutations. Eight mutations were missense. Six patients with CPS1 deficiency had neonatal type. The peak ammonia level, initial glutamate level, and accompanying rate of irreversible neurological damages were highest in patients with CPS1 deficiency. The patient with late-onset CPS1 deficiency responded dramatically to N-carbamylglutamate treatment.

CONCLUSION

The clinical manifestations of CPS1 deficiency were the most severe among UCDs. Considering the high proportion of missense mutations, responsiveness to N-carbamylglutamate would be evaluated in a future study.

Case Report: Mevalonic Aciduria Complicated by Acute Myeloid Leukemia After Hematopoietic Stem Cell Transplantation

Mevalonic aciduria (MA) is the most severe clinical subtype of mevalonate kinase deficiency (MKD) caused by an inherited defect in the mevalonate pathway. The treatment of MKD focuses on the suppression of recurrent hyperinflammatory attacks using anti-inflammatory drugs. Recently, allogeneic hematopoietic stem cell transplantation (HCT) was shown to successfully ameliorate autoinflammatory attacks in patients with MKD. Here, we report a case of an infant who showed severe recurrent systemic inflammation and was diagnosed with MA. Although she responded to steroids, her symptoms relapsed after the dose was tapered, and organ deterioration occurred. Therefore, at the age of 11 months, HCT from a matched, unrelated donor was performed for curative treatment. However, at 50 days after transplantation, acute myeloid leukemia was diagnosed, which was chemo-refractory. A second HCT from her haploidentical father was performed to treat the acute myeloid leukemia, but the patient died of sepsis on day 4 after transplantation. This is the first report of malignancy following HCT for MA. Our findings suggest that normalizing the mevalonate pathway after HCT in patients with MKD impacts patients differently depending on the clinical spectrum and severity of disease.

Identification of FOXG1 mutations in infantile hypotonia and postnatal microcephaly

ABSTRACT

FOXG1, located at chromosome 14q12, is critical for brain development, and patients with FOXG1 mutation exhibit developmental encephalopathy with high phenotypic variability, known as FOXG1 syndrome. Here, we report 3 cases of FOXG1 syndrome that presented with infantile hypotonia and microcephaly.A total of 145 children with developmental delay and/or hypotonia were evaluated by whole-exome sequencing (WES) in the pediatric neurology clinic and medical genetics center at Asan Medical Center Children's Hospital, from 2017 to 2019. Each FOXG1 mutation was confirmed by Sanger sequencing. The clinical findings of each patient with FOXG1 mutation were reviewed.WES identified de-novo, pathogenic, and heterozygous FOXG1 mutations in 3 of 145 patients in our patient cohort with developmental delay and/or hypotonia. The characteristics of brain magnetic resonance imaging (MRI) were reported as callosal anomaly, decrease in frontal volume, fornix thickening, and hypoplastic olfactory bulbs. A phenotype-genotype correlation was demonstrated as a patient with a novel missense mutation, c.761A > C (p.Tyr254Ser), in the forkhead domain had better outcome and milder brain abnormalities than the other 2 patients with truncating mutation in the Groucho binding domain site, c.958delC (p.Arg320Alafs), or N-terminal domain, c.506dup (p.Lys170GlnfsThe). Importantly, all 3 patients had hypoplastic olfactory bulbs on their brain MRI, which is a distinct and previously unrecognized feature of FOXG1 syndrome.This is the first report of FOXG1 syndrome in a Korean population; this condition accounts for 2% (3 of 145 patients) of our patient cohort with developmental delays and/or hypotonia. Our report contributes to understanding this extremely rare genetic condition in the clinical and genetic perspectives.

Association between ARID2 and RAS-MAPK pathway in intellectual disability and short stature

BACKGROUND

ARID2 belongs to the Switch/sucrose non-fermenting complex, in which the genetic defects have been found in patients with dysmorphism, short stature and intellectual disability (ID). As the phenotypes of patients with ARID2 mutations partially overlap with those of RASopathy, this study evaluated the biochemical association between ARID2 and RAS-MAPK pathway.

METHODS

The phenotypes of 22 patients with either an ARID2 heterozygous mutation or haploinsufficiency were reviewed. Comprehensive molecular analyses were performed using somatic and induced pluripotent stem cells (iPSCs) of a patient with ARID2 haploinsufficiency as well as using the mouse model of Arid2 haploinsufficiency by CRISPR/Cas9 gene editing.

RESULTS

The phenotypic characteristics of ARID2 deficiency include RASopathy, Coffin-Lowy syndrome or Coffin-Siris syndrome or undefined syndromic ID. Transient ARID2 knockout HeLa cells using an shRNA increased ERK1 and ERK2 phosphorylation. Impaired neuronal differentiation with enhanced RAS-MAPK activity was observed in patient-iPSCs. In addition, Arid2 haploinsufficient mice exhibited reduced body size and learning/memory deficit. ARID2 haploinsufficiency was associated with reduced IFITM1 expression, which interacts with caveolin-1 (CAV-1) and inhibits ERK activation.

DISCUSSION

ARID2 haploinsufficiency is associated with enhanced RAS-MAPK activity, leading to reduced IFITM1 and CAV-1 expression, thereby increasing ERK activity. This altered interaction might lead to abnormal neuronal development and a short stature.

Phenotypic and molecular spectra of patients with switch/sucrose nonfermenting complex-related intellectual disability disorders in Korea

Background

The switch/sucrose nonfermenting (SWI/SNF) complex is an adenosine triphosphate-dependent chromatin-remodeling complex associated with the regulation of DNA accessibility. Germline mutations in the components of the SWI/SNF complex are related to human developmental disorders, including the Coffin–Siris syndrome (CSS), Nicolaides–Baraitser syndrome (NCBRS), and nonsyndromic intellectual disability. These disorders are collectively referred to as SWI/SNF complex-related intellectual disability disorders (SSRIDDs).

Methods

Whole-exome sequencing was performed in 564 Korean patients with neurodevelopmental disorders. Twelve patients with SSRIDDs (2.1%) were identified and their medical records were retrospectively analyzed.

Results

ARID1B, found in eight patients, was the most frequently altered gene. Four patients harbored pathogenic variants in SMARCA4, SMARCB1, ARID2, and SMARCA2. Ten patients were diagnosed with CSS, and one patient without a typical phenotype was diagnosed with ARID1B-related nonsyndromic intellectual disability. Another patient harboring the SMARCA2 pathogenic variant was diagnosed with NCBRS. All pathogenic variants in ARID1B were truncating, whereas variants in SMARCA2, SMARCB1, and SMARCA4 were nontruncating (missense). Frequently observed phenotypes were thick eyebrows (10/12), hypertrichosis (8/12), coarse face (8/12), thick lips (8/12), and long eyelashes (8/12). Developmental delay was observed in all patients, and profound speech delay was also characteristic. Agenesis or hypoplasia of the corpus callosum was observed in half of the patients (6/12).

Conclusions

SSRIDDs have a broad disease spectrum, including NCBRS, CSS, and ARID1B-related nonsyndromic intellectual disability. Thus, SSRIDDs should be considered as a small but important cause of human developmental disorders.

Dysregulated ECM remodeling proteins lead to aberrant osteogenesis of Costello syndrome iPSCs

Costello syndrome (CS) is an autosomal dominant disorder caused by mutations in HRAS. Although CS patients have skeletal abnormalities, the role of mutated HRAS in bone development remains unclear. Here, we use CS induced pluripotent stem cells (iPSCs) undergoing osteogenic differentiation to investigate how dysregulation of extracellular matrix (ECM) remodeling proteins contributes to impaired osteogenesis. Although CS patient-derived iPSCs develop normally to produce mesenchymal stem cells (MSCs), the resulting CS MSCs show defective osteogenesis with reduced alkaline phosphatase activity and lower levels of bone mineralization. We found that hyperactivation of SMAD3 signaling during the osteogenic differentiation of CS MSCs leads to aberrant expression of ECM remodeling proteins such as MMP13, TIMP1, and TIMP2. CS MSCs undergoing osteogenic differentiation also show reduced β-catenin signaling. Knockdown of TIMPs permits normal differentiation of CS MSCs into osteoblasts and enhances β-catenin signaling in a RUNX2-independent manner. Thus, this study demonstrates that enhanced TIMP expression induced by hyperactivated SMAD3 signaling impairs the osteogenic development of CS MSCs via an inactivation of β-catenin signaling.

Case of a 21-Year-Old Man With Hemoptysis, Recurrent Pneumothorax, and Cavitary Lung Lesions

CASE PRESENTATION

A 21-year-old man was admitted to our hospital with recurrent bilateral pneumothorax and hemoptysis. Three years earlier, he underwent coil embolization due to a subarachnoid hemorrhage caused by an intracerebral aneurysm rupture. Two months after the coil embolization, he underwent an emergent total colectomy due to a massive infarction of the colon. One year after the colectomy, he started to have recurrent hemoptysis, and a few months later, multiple episodes of bilateral pneumothorax that required a chest tube placement began to occur. Notably, he had a history of easy bruising. He was taking Depakote and aspirin to prevent seizure and thromboembolic complications, respectively, both of which he began taking after the coil embolization. He denied the use of any illicit drugs. The histories of his parents and sister were not remarkable.

Ehlers-Danlos syndrome presenting as cystic lung disease with recurrent pneumothorax: a case report

A 19-year-old male patient was referred to our hospital for recurrent pneumothorax. He previously experienced seven episodes of pneumothorax refractory to conventional treatment including pleurodesis and wedge resection. On admission, chest computed tomography scan showed multiple cystic lesions with surrounding ground-glass opacities and several nodules in both lungs. Detailed history revealed that the patient experienced haemoptysis whenever pneumothorax developed and had a family history of sudden death. Physical examination showed large eyes with conjunctival injection, hypermobile joints, and hyper-extensive and easily bruised skin. All these findings led to the suspicion of vascular Ehlers-Danlos syndrome (EDS). Genetic testing for the diagnosis of vascular EDS was performed and a heterozygous mutation in COL3A1 gene, c.1662+1G>A (IVS23(+1) G>A), was confirmed. Clinicians should consider vascular EDS as the differential diagnosis of cystic lung disease with recurrent pneumothorax.

Upgrading the evidence for the use of ambroxol in Gaucher disease and GBA related Parkinson: Investigator initiated registry based on real life data

Ambroxol hydrochloride is an oral mucolytic drug available over-the-counter for many years as cough medicine. In 2009 it was identified as a pharmacological chaperone for mutant glucocerebrosidase, albeit in a several-fold higher dose. Unfortunately, there have been no pharma-driven clinical trials to establish its use. Thus, real-world observational data are needed on the safety and efficacy of ambroxol for patients with Gaucher disease (GD) and GBA-Parkinson disease (GBA-PD). Clinicians treating patients with ambroxol for GD and GBA-PD were approached to collaborate in an investigator-initiated registry. Anonymized data were collected, including demographics, GD type, GD-specific therapy (when applicable), adverse events (AEs), and, when available, efficacy data. We report the data of the first 41 patients (25 females) at a median (range) age 17 (1.5-74) from 13 centers; 11 with GD type 1(four diagnosed with PD), 27 with neuronopathic GD (nGD), and three GBA mutation carriers with PD. The median (range) treatment period and maximum dose of ambroxol were 19 (1-76) months and 435 (75-1485) mg/day, respectively. One patient with type 2 GD died of her disease. No other severe AEs were reported. Twelve patients experienced AE, including minor bowel discomfort, cough, allergic reaction, mild proteinuria, dizziness and disease progression. Clinical benefits were reported in 25 patients, including stable or improved neurological status, increased physical activity, and reduced fatigue. Until the approval of specific therapies for nGD and disease-modification for GBA-PD, these preliminary data may be encouraging to physicians and patients who consider an off-label use of ambroxol.

Efficacy of Living Donor Liver Transplantation in Patients with Methylmalonic Acidemia

PURPOSE

Despite aggressive medical and nutritional management, patients with methylmalonic acidemia (MMA) often suffer from multi-organ damage. Early deceased donor liver transplantation (DDLT) has emerged as an intervention to prevent disease progression. We investigated the efficacy of living donor LT (LDLT) with a potential carrier of MMA and a small volume of graft in patients with MMA as an alternative to DDLT.

METHODS

Of five patients (three male, two female; median age 5.7 years; range, 1.3-13.7 years), four underwent carrier LDLT, while one underwent non-carrier auxiliary LDLT. All patients received pre- and post-LT continuous renal replacement therapy and were provided with minimal restriction diet according to serum MMA level after LT. MMA levels in the serum and urine, the incidence of metabolic crisis, and clinical findings before and after LT were compared.

RESULTS

The survival rate was 100% during 2.2 years of follow up period after LT. In all five cases, MMA titer in the serum after transplantation decreased with less restrictive diet. Metabolic crisis was not observed during the follow-up period. In addition, no patient showed progression of severe renal impairment requiring hemodialysis. Progression of delayed cognitive development was not observed. Social functioning with improved neuropsychiatric development was observed.

CONCLUSION

This study showed that LDLT achieved improved quality of life with less restrictive diet, therefore it could be a feasible alternative option to DDLT for the treatment of patients with MMA, even with an auxiliary LT.

Hematopoietic stem cell transplantation in an infant with dedicator of cytokinesis 8 (DOCK8) deficiency associated with systemic lupus erythematosus: A case report

INTRODUCTION

DOCK8 deficiency is a primary immunodeficiency characterized by recurrent infections, severe allergic disease, and autoimmunity. Here, we report a patient with DOCK8 deficiency that was initially presented as systemic lupus erythematosus (SLE) without recurrent infections and treated with hematopoietic stem cell transplantation (HSCT).

PATIENT CONCERNS

A 16-month-old boy with a previous history of eczema developed high fever and hand and foot swelling. Over time, multiple purpura, oral ulcers, and oliguria developed with a persistent fever. His laboratory findings showed anemia, thrombocytopenia, and coagulopathy with a high level of C-reactive protein (CRP). No definite pathogens were identified. The complement fractions C3, C4, and CH50 were low. Autoantibodies including antinuclear antibody (ANA) and anti-ds DNA antibody were positive. He definitively satisfied the 2015 ACR/SLICC revised criteria for the diagnosis of SLE (7 points out of 16); therefore, he was treated with a steroid. Lupus nephritis was confirmed by renal biopsy later. Considering the early-onset SLE, partial exome sequencing was performed.

DIAGNOSIS

One heterozygous missense variant, c.5536A>G (p.Lys1846Glu), which was inherited from his father, and heterozygous deletion of exon 1 to 8 inherited from his mother were found. Through the results of the genetic testing, the patient was confirmed to have DOCK8 deficiency.

INTERVENTIONS

At the age of 28 months, he received haploidentical HSCT from his mother as a donor.

OUTCOMES

Laboratory findings including complement fractions C3, C4, CH50, anti-ds DNA antibody, and the ANA became normal after HSCT. Currently, at 12 months post-HSCT, he is doing well, without any autoimmune features or infections.

CONCLUSIONS

DOCK8 deficiency can be presented as autoimmune disease such as SLE. Encountering a child diagnosed with SLE at a very young age, pediatricians should consider immunodeficiency syndrome including DOCK8 deficiency.

Neurofibromatosis type I: points to be considered by general pediatricians

Neurofibromatosis type 1 (NF1), a prevalent genetic disease that is transmitted in an autosomal dominant manner, is characterized by multiple cutaneous café-au-lait spots and neurofibromas as well as various degrees of neurological, skeletal, and neoplastic manifestations. The clinical features of NF1 increase in frequency with age, while the clinical diagnosis can remain undetermined in some pediatric patients. Importantly, affected patients are at risk for developing tumors of the central and peripheral nervous system. Therefore, adequate counseling for genetic testing, age-appropriate surveillance, and management are important. This review suggests several issues that should be considered to help general pediatricians provide adequate clinical care and genetic counseling to patients with NF1 and their families.

De Novo Development of mtDNA Deletion Due to Decreased POLG and SSBP1 Expression in Humans

Defects in the mitochondrial genome (mitochondrial DNA (mtDNA)) are associated with both congenital and acquired disorders in humans. Nuclear-encoded DNA polymerase subunit gamma (POLG) plays an important role in mtDNA replication, and proofreading and mutations in POLG have been linked with increased mtDNA deletions. SSBP1 is also a crucial gene for mtDNA replication. Here, we describe a patient diagnosed with Pearson syndrome with large mtDNA deletions that were not detected in the somatic cells of the mother. Exome sequencing was used to evaluate the nuclear factors associated with the patient and his family, which revealed a paternal POLG mutation (c.868C > T) and a maternal SSBP1 mutation (c.320G > A). The patient showed lower POLG and SSBP1 expression than his healthy brothers and the general population of a similar age. Notably, c.868C in the wild-type allele was highly methylated in the patient compared to the same site in both his healthy brothers. These results suggest that the co- deficient expression of POLG and SSBP1 genes could contribute to the development of mtDNA deletion.

Association between mortality risk and the number, location, and sequence of subsequent fractures in the elderly

The mortality risk showed a positive correlation as the number of subsequent fractures increased. Hip fracture showed the greatest association with mortality risk, followed by vertebral fracture. For the combination of hip and vertebral fracture, a hip fracture after a vertebral fracture showed the highest mortality risk.

INTRODUCTION

It is unclear whether subsequent fractures or a certain location and sequence of subsequent fractures are associated with mortality risk in the elderly. We aimed to investigate the relationship between subsequent fractures and mortality risk.

METHODS

Using the Korean National Health Insurance Research Database, we analyzed the cohort data of 24,756 patients aged > 60 years who sustained fractures between 2002 and 2013. Cox regression was used to assess the mortality risk associated with the number, locations, and sequences of subsequent fractures.

RESULTS

Mortality hazard ratios (HRs) for women and men were shown to be associated with the number of subsequent fractures (one, 1.63 (95% confidence interval [CI], 1.48-1.80) and 1.42 (95% CI, 1.28-1.58); two, 1.75 (95% CI, 1.47-2.08) and 2.03 (95% CI, 1.69-2.43); three or more, 2.46(95% CI, 1.92-3.15) and 1.92 (95% CI, 1.34-2.74), respectively). For women, the mortality risk was high when hip (HR, 2.49; 95% CI, 1.80-3.44) or vertebral (HR, 1.40; 95% CI, 1.03-1.90) fracture occurred as a second fracture. Compared with a single hip fracture, there was a high mortality risk in the group with hip fracture after the first vertebral fracture (HR, 2.90; 95% CI, 1.86-4.54), followed by vertebral fracture after the first hip fracture (HR, 1.90; 95% CI, 1.12-3.22).

CONCLUSION

The mortality risk showed a positive correlation as the number of subsequent fractures increased. Hip fracture showed the greatest association with mortality risk, followed by vertebral fracture. For the combination of hip and vertebral fracture, a hip fracture after a vertebral fracture showed the highest mortality risk.

Diagnosis of Schaaf-Yang syndrome in Korean children with developmental delay and hypotonia

Schaaf-Yang syndrome (SYS) is a recently identified disorder caused by a loss-of-function mutation in a maternally imprinted gene, MAGEL2, at 15q11.2q13. Due to its extreme rarity and wide range of clinical severity, clinical suspicion is difficult for a physician. In the current study, its frequency among the Korean pediatric patients with developmental delay (DD) or intellectual disability (ID) was assessed. As the first report of Korean patients with SYS, our study aims to increase the awareness of this condition among the physicians taking care of the pediatric patients with DD/ID and hypotonia.The patients diagnosed with SYS by whole-exome sequencing (WES) among the 460 Korean pediatric patients with DD/ID were included, and their clinical and molecular features were reviewed.Four patients (0.9%) were diagnosed with SYS. Profound DD (4 patients), multiple anomalies including joint contractures and facial dysmorphism (4 patients), generalized hypotonia (3 patients), and severe respiratory difficulty requiring mechanical ventilation (3 patients) were noted in most cases, similar to those in previous reports. Sleep apnea (2 patients), autistic features (2 patients), a high grade of gastroesophageal reflux (1 patient), and seizures (1 patient) were found as well. A total of 3 different truncating MAGEL2 mutations were identified. A previously-reported mutation, to be the most common one, c.1996dupC, was found in 2 patients. The other 2 mutations, c.2217delC and c.3449_3450delTT were novel mutations. As MAGEL2 is maternally imprinted, 2 patients had inherited the MAGEL2 mutation from their respective healthy fathers.SYS is an extremely rare cause of DD/ID. However, hypotonia, joint contractures, profound DD/ID and facial dysmorphism are the suggestive clinical features for SYS. As a maternally imprinted disorder, it should be reminded that SYS may be inherited in form of a mutation from a healthy father.

Clinical Application of Whole Exome Sequencing to Identify Rare but Remediable Neurologic Disorders

Background: The aim of this study was to describe the application of whole exome sequencing (WES) in the accurate genetic diagnosis and personalized treatment of extremely rare neurogenetic disorders. Methods: From 2017 to 2019, children with neurodevelopmental symptoms were evaluated using WES in the pediatric neurology clinic and medical genetics center. The clinical presentation, laboratory findings including the genetic results from WES, and diagnosis-based treatment and outcomes of the four patients are discussed. Results: A total of 376 children with neurodevelopmental symptom were evaluated by WES, and four patients (1.1%) were diagnosed with treatable neurologic disorders. Patient 1 (Pt 1) showed global muscle hypotonia, dysmorphic facial features, and multiple anomalies beginning in the perinatal period. Pt 1 was diagnosed with congenital myasthenic syndrome 22 of PREPL deficiency. Pt 2 presented with hypotonia and developmental arrest and was diagnosed with autosomal recessive dopa-responsive dystonia due to TH deficiency. Pt 3, who suffered from intractable epilepsy and progressive cognitive decline, was diagnosed with epileptic encephalopathy 47 with a heterozygous FGF12 mutation. Pt 4 presented with motor delay and episodic ataxia and was diagnosed with episodic ataxia type II (heterozygous CACNA1A mutation). The patients’ major neurologic symptoms were remarkably relieved with pyridostigmine (Pt 1), levodopa (Pt 2), sodium channel blocker (Pt 3), and acetazolamide (Pt 4), and most patients regained developmental milestones in the follow-up period (0.4 to 3 years). Conclusions: The early application of WES helps in the identification of extremely rare genetic diseases, for which effective treatment modalities exist. Ultimately, WES resulted in optimal clinical outcomes of affected patients.

The GBA p.G85E mutation in Korean patients with non-neuronopathic Gaucher disease: founder and neuroprotective effects

Background

Gaucher disease (GD) is caused by a deficiency of β-glucocerebrosidase, encoded by GBA. Haplotype analyses previously demonstrated founder effects for particular GBA mutations in Ashkenazi Jewish and French-Canadian populations. This study aimed to investigate the clinical characteristics and mutation spectrum of GBA in Korean GD patients and to identify founder effect of GBA p.G85E in non-neuronopathic GD patients.

Results

The study cohort included 62 GD patients from 58 unrelated families. Among them, 18 patients from 17 families harbored the p.G85E mutation. Haplotype analysis was performed for 9 probands and their parents for whom DNA samples were available. In 58 unrelated probands, the GBA mutation p.L483P was the most common (30/116 alleles, 26%), followed by p.G85E (16%), p.F252I (13%), and p.R296Q (9%). The median age at diagnosis of the 18 patients harboring the p.G85E mutation was 3.8 (range 1.2–57) years. No patients developed neurological symptoms during follow-up periods of 2.2–20.3 (median 13.9) years. The size of the shared haplotype containing GBA p.G85E was 732 kbp, leading to an estimated age of 3075 years.

Conclusion

The GBA p.G85E mutation, which appears to be neuroprotective despite producing distinctive visceromegaly and skeletal symptoms, exhibited a potential founder effect in Korean GD patients.

Clinical and molecular spectra of BRAF-associated RASopathy

Noonan syndrome (NS) and cardio-facio-cutaneous (CFC) syndrome are the most common subtypes of RASopathy. As an effector of Ras, BRAF is one of the molecules responsible for RASopathy. We investigated the phenotypic and genotypic features of 26 patients with BRAF-associated RASopathy. The clinical diagnoses were CFC (n = 21, 80.8%), NS (n = 3, 11.5%), NS/CFC (n = 1, 3.8%), and undefined syndromic intellectual disability (ID) (n = 1, 3.8%). The mostly shared phenotypes were ID (90.5%), cutaneous manifestations (84.6%), congenital heart defects (76.9%), short stature (76.9%), and dysmorphic features such as short neck (65.4%) and low-set ears (65.4%). Importantly, moderate to severe ID (57.1%) and epilepsy (26.9%) were noted. Eighteen different missense mutations were found, including a novel mutation, p.Phe498Tyr. p.Gln257Arg (n = 9, 34.6%) was the most common mutation, and the mutations were clustered in the cysteine-rich domain or protein kinase domain. A review of previously reported cases along with our findings revealed the existence of multiple sub-phenotypes of RASopathy within a single genotype, indicating that BRAF-associated RASopathy is not variant-specific. Our study further delineated the diverse and expanded clinical phenotypes of BRAF-associated RASopathy with their molecular genetic characteristics.

Leukocyte-dependent effects of platelet-rich plasma on cartilage loss and thermal hyperalgesia in a mouse model of post-traumatic osteoarthritis

OBJECTIVE

Platelet-rich plasma (PRP) is an emerging therapeutic strategy for treatment of osteoarthritis (OA); however, there is a lack of preclinical and clinical evidence for its efficacy and its mechanism of action is unclear. In the current study, we utilized leukocyte poor-PRP (LP-PRP) and leukocyte rich-PRP (LR-PRP) to mimic clinical point of care formulations and assessed their potential to alter disease progression in a mouse model of post-traumatic OA.

METHOD

Three-month-old wild-type male FVB/N mice received destabilization of the medial meniscus (DMM) surgery to induce OA. To assess the efficacy of LP-PRP and LR-PRP, mice were given intraarticular injections at 2-, 7- and 28-days post-surgery. Mice were then assessed at 5-, 9-, and 13-weeks post-surgery for changes in chronic pain using the hot plate nociceptive assay. At 14-weeks, OA pathogenesis was evaluated using histology and phase-contrast μCT.

RESULTS

Treatment with LP-PRP and to a lesser extent LR-PRP preserved cartilage volume and surface area compared to phosphate-buffered saline (PBS) as measured by phase-contrast μCT. However, both treatments had higher Osteoarthritis Research Society International (OARSI) and synovitis scores compared to sham, and neither substantially improved scores compared to PBS controls. With respect to thermal hyperalgesia, PBS-treated mice displayed reduced latency to response compared to sham, and LR-PRP but not LP-PRP improved latency to response at 5-, 9- and 13-weeks post-surgery compared to PBS.

CONCLUSION

The results of this study suggest that effects of PRP therapy on OA progression and disease-induced hyperalgesia may be leukocyte-dependent. And while LP-PRP and to a lesser extent LR-PRP protect from volume and surface loss, significant pathology is still seen within OA joints. Future work is needed to understand how the different components of PRP effect OA pathogenesis and pain, and how these could be modified to achieve greater therapeutic efficacy.