Clinical and genetic spectrum of GSD type 6 in Korea.

BACKGROUND: Glycogen storage disease type VI (GSD VI) is a rare disease in which liver glycogen metabolism is impaired by mutations in the glycogen phosphorylase L (PYGL). This study aimed to examine the clinical features, genetic analyses, and long-term outcomes of patients with GSD VI in Korea. METHODS: From January 2002 to November 2022, we retrospectively reviewed patients diagnosed with GSD VI using a gene panel at Seoul National University Hospital. We investigated the clinical profile, liver histology, molecular diagnosis, and long-term outcomes of patients with GSD VI. RESULTS: Five patients were included in the study. The age at onset was 18-30 months (median, 21 months), and current age was 3.7-17 years (median, 11 years). All patients showed hepatomegaly, elevated liver transaminase activity, and hypertriglyceridaemia. Hypercholesterolaemia and fasting hypoglycaemia occurred in 60% and 40% of patients, respectively. Ten variants of PYGL were identified, of which six were novel: five missense (p.[Gly607Val], p.[Leu445Pro], p.[Gly695Glu], p.[Val828Gly], p.[Tyr158His]), and one frameshift (p.[Arg67AlafsTer34]). All patients were treated with a high-protein diet, and four also received corn starch. All patients showed improved liver function tests, hypertriglyceridaemia, hepatomegaly, and height z score. CONCLUSIONS: The GSD gene panel is a useful diagnostic tool for confirming the presence of GSD VI. Genetic heterogeneity was observed in all patients with GSD VI. Increased liver enzyme levels, hypertriglyceridaemia, and height z score in patients with GSD VI improved during long-term follow-up.

[Clinical features and genetic analysis of a child with glycogen storage disease type VI].

OBJECTIVE: To explore the clinical features and genetic etiology of a child with glycogen storage disease VI (GSD-VI). METHODS: Clinical data and laboratory results of the patient were collected. Whole exome sequencing (WES) was carried out for the patient. Candidate variant and its parental origin was verified by Sanger sequencing. RESULTS: The patient was a 3-year-and-9-month old boy whom has featured abdominal distention, hepatomegaly, short stature and elevated hepatic transaminase. WES revealed the he has harbored compound heterozygous variants of the PYGL gene, namely c.697G>A (p.Gly233Ser) and c.320dupA (p.Asn107fs). Sanger sequencing has verified that the two variants have derived from his father and mother, respectively. The c.320dupA (p.Asn107fs) variant was unreported previously. CONCLUSION: The compound heterozygous variants of the PYGL gene probably underlay the GSD-VI in this patient. Above finding has enriched the spectrum of PYGL gene variants and provided a basis for the treatment and genetic counseling.

Liver transplantation in glycogen storage disease: a single-center experience.

BACKGROUND: Glycogen storage diseases (GSDs) are inherited glycogen metabolic disorders which have various subtypes. GSDs of type I, III, IV, VI, and IX show liver involvement and are considered as hepatic types of GSDs. Thus, liver transplantation (LT) has been proposed as a final therapy for these types of GSD. LT corrects the primary hepatic enzyme defect; however, the long-term outcomes of LT in these patients have not been extensively evaluated so far. There are few reports in the English literature about the outcome of GSD patients after LT. There has been no report from Iran. The present retrospective study aimed to evaluate the long-term outcomes of eight patients with GSD types I, III, and IV who underwent LT in the affiliated hospitals of Shiraz University of Medical Sciences, from March 2013 to June 2021. During this period, there were no patients with GSD VI and IX identified in this center. RESULTS: The median time of diagnosis of the GSDs and at transplant was 1 year and 11 years, respectively. All eight transplanted patients were alive at the time of follow-up in this study. None of them required a re-transplant. All of the patients showed normalized liver enzymes after LT with no sign of hypoglycemia. CONCLUSIONS: LT is an achievable treatment for end-stage hepatic involvement of GSDs with a cure for metabolic deficiency. Our experience in these eight patients shows a favorable outcome with no mortality and no major complication.

Diagnosis and follow-up of glycogen storage disease (GSD) type VI from the largest GSD center in China.

Glycogen storage disease (GSD) Type VI is a glycogenolysis disorder caused by variants of PYGL. Knowledge about this disease is limited because only approximately 50 cases have been reported. We investigated the clinical profiles, molecular diagnosis, and treatment outcomes in patients with GSD VI from 2000 to 2021. The main initial clinical features of this cohort include hepatomegaly, short stature, elevated liver transaminases, hypertriglyceridemia, fasting hypoglycemia, and hyperuricemia. After uncooked cornstarch treatment, the stature and biochemical parameters improved significantly (p < 0.05). However, hyperuricemia recurred in most patients during adolescence. Among the 56 GSD VI patients, 54 biallelic variants and two single allelic variants of PYGL were identified, of which 43 were novel. There were two hotspot variants, c.1621-258_2178-23del and c.2467C>T p.(Gln823*), mainly in patients from Southwest and South China. c.1621-258_2178-23del is a 3.6 kb deletion that results in an out-of-frame deletion r.1621_2177del and an in-frame deletion r.1621_2265del. Our data show for the first time that long-term monitoring of uric acid is recommended for older GSD VI patients. This study also broadens the variant spectrum of PYGL and indicates that there are two hot-spot variants in China.

Clinical, pathological and molecular spectrum of patients with glycogen storage diseases in Pakistan.

OBJECTIVES: Evaluation of clinical, biochemical and molecular analysis of Pakistani patients with hepatic GSDs. METHODS: Medical charts, biochemical, histopathological and molecular results of patients with hepatic GSD were reviewed. RESULTS: Out of 55 GSD patients, 41 (74.5%) were males and 14 (25.5%) were females with consanguinity in 50 (91%) patients. The median age of initial symptoms, clinic diagnosis and molecular diagnosis were 450 (IQR: 270-960), 1,095 (IQR: 510-1,825) and 1717 (IQR: 796-3,011) days, respectively. Molecular analysis and enzyme activity was available for 33 (60%) and two patients, respectively. GSD III (n=9) was most prevalent followed by GSD Ib (n=7), GSD IXc (n=6), GSD VI (n=4), GSD Ia (n=3), GSD XI (n=3), GSD IXb (n=2) and GSD IXa (n=1). In patients (n=33) who underwent molecular analysis; 19 different variants in eight genes associated with GSD were identified. We also report five novel variants, two in SLC37A4, one in AGL and two in PYGL contributing to the diagnosis of GSD Ib, GSD III and GSD VI, respectively. CONCLUSIONS: Fifty-five patients of GSDs in 26 families from a single care provider indicate a relatively high frequency of GSD in Pakistan, with multiple unrelated families harboring identical disease-causing variants, on molecular analysis, including two known pathogenic variants in SLC37A4 and PHKG2, and a novel variant in AGL.

[Genetic analysis of PYGL gene variants for a child with Glycogen storage disease VI].

OBJECTIVE: To explore the clinical features and genetic basis of a patient with glycogen storage disease type VI (GSD-VI). METHODS: Clinical data of the patient was collected. Genomic DNA was extracted from peripheral blood samples of the proband and his parents. Genetic variants were detected by using whole exome sequencing. Candidate variants were verified by Sanger sequencing followed by bioinformatics analysis. RESULTS: The proband presented fasting hypoglycemia, hepatomegaly, growth retardation, transaminitis, metabolic acidosis and hyperlactatemia. Liver biopsy indicated GSD. Novel compound heterozygous PYGL gene variants (c.2089A>G/c.158_160delACT) were detected in the proband. Compound heterozygosity was confirmed by Sanger sequencing of the patient's genomic DNA. Provean and MutationTaster predicted the two variants as deleterious and the variant sites are highly conserved. CONCLUSION: The compound heterozygous variants (c.2089A>G/c.158_160delACT) of PYGL gene probably underlay the GSD in the patient. The two novel variants have expanded the spectrum of PYGL gene variants and provided the basis for genetic counseling of the family.

Genetic analysis of PYGL gene variants for a child with Glycogen storage disease VI / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical features and genetic basis of a patient with glycogen storage disease type VI (GSD-VI).@*METHODS@#Clinical data of the patient was collected. Genomic DNA was extracted from peripheral blood samples of the proband and his parents. Genetic variants were detected by using whole exome sequencing. Candidate variants were verified by Sanger sequencing followed by bioinformatics analysis.@*RESULTS@#The proband presented fasting hypoglycemia, hepatomegaly, growth retardation, transaminitis, metabolic acidosis and hyperlactatemia. Liver biopsy indicated GSD. Novel compound heterozygous PYGL gene variants (c.2089A>G/c.158_160delACT) were detected in the proband. Compound heterozygosity was confirmed by Sanger sequencing of the patient's genomic DNA. Provean and MutationTaster predicted the two variants as deleterious and the variant sites are highly conserved.@*CONCLUSION@#The compound heterozygous variants (c.2089A>G/c.158_160delACT) of PYGL gene probably underlay the GSD in the patient. The two novel variants have expanded the spectrum of PYGL gene variants and provided the basis for genetic counseling of the family.

The Phenotypic and Genetic Spectrum of Glycogen Storage Disease Type VI.

Glycogen storage disease type VI (GSD VI) is an autosomal recessive disorder of glycogen metabolism due to mutations in the glycogen phosphorylase gene (PYGL), resulting in a deficiency of hepatic glycogen phosphorylase. We performed a systematic literature review in order to collect information on the clinical phenotypes and genotypes of all published GSD VI patients and to compare the data to those for GSD IX, a biochemically and clinically very similar disorder caused by a deficiency of phosphorylase kinase. A total of 63 genetically confirmed cases of GSD VI with clinical information were identified (median age: 5.3 years). The age at presentation ranged from 5 weeks to 38 years, with a median of 1.8 years. The main presenting symptoms were hepatomegaly and poor growth, while the most common laboratory findings at initial presentation comprised elevated activity of liver transaminases, hypertriglyceridemia, fasting hypoglycemia and postprandial hyperlactatemia. Liver biopsies (n = 37) showed an increased glycogen content in 89.2%, liver fibrosis in 32.4% and early liver cirrhosis in 10.8% of cases, respectively. No patient received a liver transplant, and one successful pregnancy was reported. Our review demonstrates that GSD VI is a disorder with broad clinical heterogeneity and a small number of patients with a severe phenotype and liver cirrhosis. Neither clinical nor laboratory findings allow for a differentiation between GSD VI and GSD IX. Early biochemical markers of disease severity or clear genotype phenotype correlations are missing. Given the overall benign and unspecific phenotype and the need for enzymatic or genetic analyses for confirmation of the diagnosis, GSD VI is likely underdiagnosed. With new treatment approaches in sight, early, pre-symptomatic diagnosis, especially with respect to hepatic cirrhosis, will become even more important.

Glycogen storage disease type VI with a novel PYGL mutation: Two case reports and literature review.

RATIONALE: Glycogen storage disease (GSD) type VI is a rare disease caused by the inherited deficiency of liver phosphorylase. PATIENT CONCERNS: The proband, a 61-month-old Chinese boy, manifested intermittent hematochezia, growth retardation, hepatomegaly, damage of liver function, mild hypoglycemia, and hyperlactatemia. The other patient was a 107-month-old Chinese girl with growth retardation, hepatomegaly, mild hypoglycemia, and hyperlactatemia. In order to further confirm the diagnosis, we conducted a liver biopsy and detected blood samples for their gene using IDT exon chip capture and high-throughput sequencing. DIAGNOSES: According to the clinical symptoms, physical examination, laboratory examinations, liver biopsy, and the genetic test finding, the 2 patients were diagnosed GSD VI. INTERVENTIONS: They were treated mainly with uncooked cornstarch. OUTCOMES: There were 2 mutations of PYGL gene in this pedigree. c.2467C>T (p. Q823X) and c.2178-2A>C occurred both in the proband and his second sister. LESSONS: As a novel mutation, c.2178-2A>C enriches the mutation spectrum of PYGL gene. The different degrees of elevated lactate is an unusual phenotype in GSD VI patients. It is not clear if this is caused by the new mutation of c. 2178-2A > C. Long-term complications remains to be observed.

Liver histology in children with glycogen storage disorders type VI and IX.

BACKGROUND: Glycogen storage diseases (GSD) type VI and IX are caused by liver phosphorylase system deficiencies and the two types are clinically indistinguishable. AIM: As the role of liver biopsy is increasingly questioned, we aim to assess its current value in clinical practice. METHODS: We retrospectively reviewed children with diagnosis of GSD VI and IX at a paediatric liver centre between 2001 and 2018. Clinical features, molecular analysis and imaging were reviewed. Liver histology was reassessed by a single histopatologist. RESULTS: Twenty-two cases were identified (9 type VI, 9 IXa, 1 IXb and 3 IXc). Features at presentation were hepatomegaly (95%), deranged AST (81%), short stature (50%) and failure to thrive (4%). Liver biopsy was performed in 19 patients. Fibrosis varied in GSD IXa with METAVIR score between F1-F3 and ISHAK score of F2-F5. METAVIR score was F2-F3 in GSD VI and F3-F4 in GSD IXc. Hepatocyte glycogenation, mild steatosis, lobular inflammatory activity and periportal copper binding protein staining were also demonstrated. CONCLUSIONS: Although GSD VI and IX are considered clinically mild, chronic histological changes of varying severity could be seen in all liver biopsies. Histopathological assessment of the liver involvement is superior to biochemical parameters, but definitive classification requires a mutational analysis.

Diagnosis of hepatic glycogen storage disease patients with overlapping clinical symptoms by massively parallel sequencing: a systematic review of literature.

BACKGROUND: Glycogen storage diseases (GSDs) with liver involvement are complex disorders with similar manifestations. Currently, the main diagnostic methods such as tissue diagnosis, either histopathology or enzyme assay, are invasive. Meanwhile, GSDs are diseases with significant genetic heterogeneity, and gene-sequencing methods can be more useful. This systematic review aims to review the literature to assess the value of massively parallel sequencing in the diagnosis of GSDs on patients with previously undiagnosed hepatic involvement. METHODS: Relevant studies identified in the MEDLINE/PubMed, EMBASE, Cochrane Library, Scopus, and Web of Science Core Collection databases up to July 2019 with no time and language restrictions. Publications were included in the review if they analyzed GSDs with hepatic involvement (GSD I, GSD III, GSD IV, GSD VI, GSD IX), using targeted gene sequencing (TGS) or exome sequencing (ES). RESULTS: Eleven studies were included in this systematic review. ES demonstrated a 93% diagnostic yield. These methods correctly distinguished all types of pathogenic variants. The diagnostic yield of the TGS method was around 79.7%. CONCLUSIONS: According to our results, TGS analysis can be considered as the first-line diagnostic method with valuable results and ES can be used to diagnose complex cases of GSD with liver involvement. Overall, these molecular methods are considered as accurate diagnostic tools, which expedite correct diagnosis and treatment with significant cost-effectiveness by reducing unnecessary and inaccurate tests. PROSPERO REGISTRATION: CRD42020139931. Registered 8 January 2020.

A Novel, Recurrent, 3.6-kb Deletion in the PYGL Gene Contributes to Glycogen Storage Disease Type VI.

The PYGL gene is the only established gene known to cause glycogen storage disease type VI (GSD6), which is a rare autosomal recessive disorder associated with hepatomegaly, elevated levels of hepatic transaminases, and hypoglycemia. Extended bioinformatics analysis was performed on the exome sequencing data of 5 patients who were clinically diagnosed as having or highly suspected of having GSD, and a single heterozygous pathogenic or likely pathogenic or rare variant of uncertain significance single-nucleotide variant was identified on the PYGL gene. A recurrent, novel, 3.6-kb deletion involving exons 14 to 17 of PYGL was identified in three of the five patients. Together with the two novel and one established stop-gain SNVs, they were diagnosed as compounds heterozygous of PYGL variants and confirmed as GSD6. The detected 3.6-kb deletion was further screened in a Chinese cohort of 31,317 individuals without hepatic abnormalities, and 10 carriers were identified, showing an allele frequency of 0.016%. Compared with the previously established 47 PYGL pathogenic or likely pathogenic SNVs, the novel pathogenic deletion had the second highest allele frequency among the population. This recurrent, novel, 3.6-kb deletion improved the molecular diagnostic rate of the GSD6. The relatively high frequency of the variant suggests that it is a potential mutation hotspot in patients with GSD6.

Glycogen storage disease type VI can progress to cirrhosis: ten Chinese patients with GSD VI and a literature review.

Objectives The aim of our study is to systematically describe the genotypic and phenotypic spectrum of Glycogen storage disease type VI (GSD VI), especially in Chinses population.  Methods We retrospectively analyzed ten Chinese children diagnosed as having GSD VI confirmed by next generation sequencing in Children's Hospital of Fudan University and Jinshan Hospital of Fudan University. We described the genotypic and phenotypic spectrum of GSD VI through the clinical and genetic data we collected. Moreover, we conducted a literature review, and we compared the genotypic and phenotypic spectrum of GSD VI between Chinese population and non Chinese population.  Results For the first time, we found that four Chinese patients showed cirrhosis in liver biopsy characterized by the formation of regenerative nodules. In addition, c.772+1G>A and c.1900G>C, p.(Asp634His) were recurrent in three Chinese families and four European families respectively indicating that the genotypic spectrum of PYGL gene may vary among the population. Furthermore, we identified seven novel variants in PYGL gene.  Conclusions Our study enriched the genotypic and phenotypic spectrum of GSD VI, and provided a new clue for management of GSD VI.

Novel PYGL mutations in Chinese children leading to glycogen storage disease type VI: two case reports.

BACKGROUND: PYGL mutations can cause liver phosphorylase deficiency, resulting in a glycogenolysis disorder, namely, glycogen storage disease (GSD) VI. The disease is rarely reported in the Chinese population. GSD VI is mainly characterized in untreated children by hepatomegaly, growth retardation and elevated liver transaminases. CASE PRESENTATION: In this study, we report two GSD VI patients with growth retardation and abnormal liver function. There was no obvious hepatomegaly for one of them. Whole exome sequencing (WES) combined with copy number variation analysis was performed. We found a novel homozygous gross deletion, c.1621-258_2178-23del, including exons 14-17 of PYGL in patient 1. The exons 14-17 deletion of PYGL resulted in an in-frame deletion of 186 amino acids. Compound heterozygous mutations of PYGL were identified in patient 2, including a novel missense mutation c.1832C > T/p.A611V and a recurrent nonsense mutation c.280C > T/p.R94X. After treatment with uncooked cornstarch (UCS) 8 months for patient 1 and 13 months for patient 2, the liver transaminases of both patients decreased to a normal range and their stature was improved. However, patient 1 still showed mild hypertriglyceridemia. CONCLUSIONS: We describe two GSD VI patients and expand the spectrum of PYGL mutations. Patient 1 in this study is the first GSD VI case that showed increased transaminases without obvious hepatomegaly due to a novel homozygous gross deletion of PYGL identified through WES.

Glycogen storage disease type VI: clinical course and molecular background.

Glycogen storage disease type VI (GSD-VI; also known as Hers disease, liver phosphorylase deficiency) is caused by mutations in the gene coding for glycogen phosphorylase (PYGL) leading to a defect in the degradation of glycogen. Since there are only about 40 patients described in literature, our knowledge about the course of the disease is limited. In order to evaluate the long-term outcome of patients with GSD-VI, an observational retrospective case study of six patients was performed at the University Children's Hospital Zurich. The introduction of small, frequent meals as well as cornstarch has led to normal growth in all patients and to normalization of liver transaminases in most patients. After starting the dietary regimen, there were no signs of hypoglycemia. However, three of six patients showed persistent elevation of triglycerides. Further, we identified four novel pathogenic PYGL mutations and describe here their highly variable impact on phosphorylase function.Conclusions: After establishing the diagnosis, dietary treatment led to metabolic stability and to prevention of hypoglycemia. Molecular genetics added important information for the understanding of the clinical variability in this disease. While outcome was overall excellent in all patients, half of the patients showed persistent hypertriglyceridemia even after initiating treatment.What is Known:• Glycogen storage disease type VI (GSD-VI) is a metabolic disorder causing a defect in glycogen degradation. Dietary treatment normally leads to metabolic stability and prevention of hypoglycemia.• However, our knowledge about the natural course of patients with GSD-VI is limited.What is New:• While outcome was overall excellent in all patients, half of the patients showed persistent hypertriglyceridemia even after initiating treatment.• Molecular genetics added important information for the understanding of the clinical variability in this disease.

A Case of Paradoxical Flare of Pustular Psoriasis after Ustekinumab Therapy / 대한피부과학회지

Biologics are the most advanced treatment for psoriasis. Ustekinumab, one of the biologics for psoriasis, is a human monoclonal antibody that binds to the p40 subunit of interleukin-12 and interleukin-23. A 41-year-old woman with a 17-year history of plaque psoriasis and psoriatic arthritis presented with worsening lesions. The patient had previously been treated with a number of topical and systemic medications and narrow band ultraviolet B. However, none of the treatments consistently controlled her disease. Thus, treatment with ustekinumab 45 mg via subcutaneous injection was initiated. Approximately 7 days after the first treatment, she experienced a flare with generalized pustules in her whole body. The condition was controlled with systemic steroid treatment. The patient was subsequently treated with adalimumab, and improvement in her plaque and pustular lesions was noted. Herein, we report a case of psoriasis that flared up after ustekinumab therapy, which was accompanied by a morphological change from plaque to pustular lesions.

Glycogen Storage Disease Type VI With a Novel Mutation in PYGL Gene.

BACKGROUND: Glycogen storage disease type VI (GSD-VI) presents with failure to thrive and also fibrosis in some cases, without cirrhosis. CASE CHARACTERISTICS: 2½-year-old girl presented with short stature, transaminase elevation and significant fibrosis, suggesting GSD-III. OBSERVATION: A pathogenic mutation in PYGL gene suggested GSD-VI. MESSAGE: GSD-VI should be a differential diagnosis whenever GSD-III is suspected.

A Case of Catatonia Later Diagnosed with NMDA Receptor Encephalitis / 대한정신분열병학회지

We report a case of a young female patient with catatonic features who later turned out to be suffering from an anti-NMDA (N-methyl-D-aspartate)-receptor-antibody encephalitis. A previously healthy 21-year-old woman was admitted to psychiatric inpatient care presenting with acute psychotic behavior with catatonic features. Laboratory tests of serum and CSF (Cerebrospinal fluid), EEG (Electroencephalogram), brain MRI (Magnetic Resonance Imaging) were unremarkable except vague slow wave on EEG. However, subtle cognitive impairment at the bedside examination suggested further imaging studies to rule out possible organic etiology like autoimmune encephalitis. Brain PET (Positron Emission Tomography) and SPECT (Single Photon Emission Computed Tomography) suggested probable inflammation in the brain. In case of autoimmune encephalitis, given the severity of symptoms and worsening course, steroid pulse therapy was initiated promptly even though the diagnosis was not confirmed but presumed at that time. She recovered completely with steroid therapy. Later her disease turned out to be anti-NMDA-receptor-antibody encephalitis by the antibody test which was not available at the time of admission. Psychiatrists need to be aware of autoimmune encephalitis like anti-NMDA-receptor-antibody encephalitis in the differential diagnosis of acute psychosis with catatonic features. Subtle cognitive impairment which tends to be overlooked due to catatonic features might be a clue to suspect the organic etiology.

Relapsed Wilms' tumor with multiple brain metastasis / 소아과

Wilms' tumor is the most common malignant renal tumor in childhood. The brain metastasis of a Wilms' tumor with anaplastic histopathology is rare. We present the case of an 8-year-old girl with Wilms' tumor, who presented with multiple brain metastases 5 years after her primary diagnosis. The brain masses were diagnosed after a generalized tonic-clonic seizure attack. The big solid mass in the cerebellum was resected, and whole-brain radiotherapy was performed, after which, she succumbed to her disease. In the case of clinical suspicion, cranial surveillance should be included in the routine clinical work-up for Wilms' tumor. Combined aggressive therapy (surgery+radiotherapy+chemotherapy) should be applied whenever possible, for both better survival and palliative aspects.