Gene Therapy in Patients with the Crigler-Najjar Syndrome.

BACKGROUND: Patients with the Crigler-Najjar syndrome lack the enzyme uridine diphosphoglucuronate glucuronosyltransferase 1A1 (UGT1A1), the absence of which leads to severe unconjugated hyperbilirubinemia that can cause irreversible neurologic injury and death. Prolonged, daily phototherapy partially controls the jaundice, but the only definitive cure is liver transplantation. METHODS: We report the results of the dose-escalation portion of a phase 1-2 study evaluating the safety and efficacy of a single intravenous infusion of an adeno-associated virus serotype 8 vector encoding UGT1A1 in patients with the Crigler-Najjar syndrome that was being treated with phototherapy. Five patients received a single infusion of the gene construct (GNT0003): two received 2×1012 vector genomes (vg) per kilogram of body weight, and three received 5×1012 vg per kilogram. The primary end points were measures of safety and efficacy; efficacy was defined as a serum bilirubin level of 300 µmol per liter or lower measured at 17 weeks, 1 week after discontinuation of phototherapy. RESULTS: No serious adverse events were reported. The most common adverse events were headache and alterations in liver-enzyme levels. Alanine aminotransferase increased to levels above the upper limit of the normal range in four patients, a finding potentially related to an immune response against the infused vector; these patients were treated with a course of glucocorticoids. By week 16, serum bilirubin levels in patients who received the lower dose of GNT0003 exceeded 300 µmol per liter. The patients who received the higher dose had bilirubin levels below 300 µmol per liter in the absence of phototherapy at the end of follow-up (mean [±SD] baseline bilirubin level, 351±56 µmol per liter; mean level at the final follow-up visit [week 78 in two patients and week 80 in the other], 149±33 µmol per liter). CONCLUSIONS: No serious adverse events were reported in patients treated with the gene-therapy vector GNT0003 in this small study. Patients who received the higher dose had a decrease in bilirubin levels and were not receiving phototherapy at least 78 weeks after vector administration. (Funded by Genethon and others; ClinicalTrials.gov number, NCT03466463.).

Cellular and metabolic effects of renin-angiotensin system blockade on glycogen storage disease type I nephropathy.

Glycogen Storage Disease Type I (GSDI) is an inherited disease caused by glucose-6 phosphatase (G6Pase) deficiency, leading to a loss of endogenous glucose production and severe hypoglycemia. Moreover, most GSDI patients develop a chronic kidney disease (CKD) due to lipid accumulation in the kidney. Similar to diabetic CKD, activation of renin-angiotensin system (RAS) promotes renal fibrosis in GSDI. Here, we investigated the physiological and molecular effects of RAS blockers in GSDI patients and mice. A retrospective analysis of renal function was performed in 21 GSDI patients treated with RAS blockers. Cellular and metabolic impacts of RAS blockade were analyzed in K.G6pc-/- mice characterized by G6pc1 deletion in kidneys. GSDI patients started RAS blocker treatment at a median age of 21 years and long-term treatment reduced the progression of CKD in about 50% of patients. However, CKD progressed to kidney failure in 20% of treated patients, requiring renal transplantation. In K.G6pc-/- mice, CKD was associated with an impairment of autophagy and ER stress. RAS blockade resulted in a rescue of autophagy and decreased ER stress, concomitantly with decreased fibrosis and improved renal function, but without impact on glycogen and lipid contents. In conclusion, these data confirm the partial beneficial effect of RAS blockers in the prevention of CKD in GSDI. Mechanistically, we show that these effects are linked to a reduction of cell stress, without affecting metabolism.

CIAO1 and MMS19 deficiency: A lethal neurodegenerative phenotype caused by cytosolic Fe-S cluster protein assembly disorders.

PURPOSE: The functionality of many cellular proteins depends on cofactors; yet, they have only been implicated in a minority of Mendelian diseases. Here, we describe the first 2 inherited disorders of the cytosolic iron-sulfur protein assembly system. METHODS: Genetic testing via genome sequencing was applied to identify the underlying disease cause in 3 patients with microcephaly, congenital brain malformations, progressive developmental and neurologic impairments, recurrent infections, and a fatal outcome. Studies in patient-derived skin fibroblasts and zebrafish models were performed to investigate the biochemical and cellular consequences. RESULTS: Metabolic analysis showed elevated uracil and thymine levels in body fluids but no pathogenic variants in DPYD, encoding dihydropyrimidine dehydrogenase. Genome sequencing identified compound heterozygosity in 2 patients for missense variants in CIAO1, encoding cytosolic iron-sulfur assembly component 1, and homozygosity for an in-frame 3-nucleotide deletion in MMS19, encoding the MMS19 homolog, cytosolic iron-sulfur assembly component, in the third patient. Profound alterations in the proteome, metabolome, and lipidome were observed in patient-derived fibroblasts. We confirmed the detrimental effect of deficiencies in CIAO1 and MMS19 in zebrafish models. CONCLUSION: A general failure of cytosolic and nuclear iron-sulfur protein maturation caused pleiotropic effects. The critical function of the cytosolic iron-sulfur protein assembly machinery for antiviral host defense may well explain the recurrent severe infections occurring in our patients.

Individual and Family Determinants for Quality of Life in Parents of Children with Inborn Errors of Metabolism Requiring a Restricted Diet: A Multilevel Analysis Approach.

OBJECTIVE: The objective of this study was to compare the quality of life (QoL) for parents of children with inborn errors of metabolism (IEMs) requiring a restricted diet with French population norms and investigate parental QoL determinants. STUDY DESIGN: This cross-sectional study included mothers and/or fathers of children < 18 years of age affected by IEMs requiring a restricted diet (except phenylketonuria) from January 2015 to December 2017. Parents' QoL was assessed using the World Health Organization Quality of Life BREF questionnaire and compared with age- and sex-matched reference values from the French general population. Linear mixed models were used to examine the effects of demographic, socioeconomic, disease-related, and psychocognitive factors on parental QoL, according to a 2-level regression model considering individuals (parents) nested within families. RESULTS: Of the 1156 parents invited to participate, 785 (68%) were included. Compared with the general population, parents of children with IEMs requiring a restricted diet reported a lower QoL in physical and social relationship domains but a higher QoL in the psychological domain. In the multivariate analysis, characteristics associated with poorer parental QoL included both parent-related factors (being a father, older age, more educated parent, nonworking parent, greater anxiety, seeking more social support, and using less positive thinking and problem-solving coping strategies) and family-related factors (disease complications, increased number of hospital medical providers, child's younger age, single-parent family, and lower family material wealth). CONCLUSION: Parents of children with IEMs requiring a restricted diet reported poorer QoL in physical and social relationship domains than population norms. Psychocognitive factors, beyond disease-specific and family-related characteristics, were the most important determinants influencing parental QoL and may represent essential aspects for interventions. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov: NCT02552784.

Management of copy number variants associated with incomplete penetrance and variable expressivity-Results of a French survey.

Increasing interest regarding neurodevelopmental disorders and democratization of chromosomal microarray analysis have led to growing identification of neuro-susceptibility copy number variations (CNVs). These CNVs have incomplete penetrance and variable expressivity (PIEV), which makes phenotypic features hard to predict. The French Consortium "AchroPuce" has provided a list of 17 CNVs that should be considered as PIEV CNVs. This list led to consensual French practices of healthcare professionals in postnatal diagnosis. However, no consensus was established in prenatal diagnosis and fetal pathology. 121 French health professionals were surveyed their opinions and practices regarding reporting of PIEV CNVs to patients, in order to identify key points so as to establish French recommendations. The survey showed that professionals in favor of reporting PIEV CNVs to patients in prenatal diagnosis and fetal pathology (respectively, 76% and 84% of respondents) considered highlighted that multidisciplinary consultation is the main point-of-care management before family survey. This statement is close to recommendations published worldwide. As a consequence, multidisciplinary expertise should be the basis of French recommendations concerning the reporting of PIEV CNVs and genetic counseling in prenatal diagnosis and fetal pathology.

Determinants of Quality of Life in Children with Inborn Errors of Metabolism Receiving a Restricted Diet.

OBJECTIVE: To investigate the determinants of quality of life (QoL) in children with inborn errors of metabolism with restricted diet (IEMRDs) using a single theory-based multidimensional model. STUDY DESIGN: In this multicenter cross-sectional study, data from children aged 8-17 years with IEMRDs (except phenylketonuria) and their parents were collected from January 2015 to December 2017. Measurements included a child's self-reported QoL, self-rated behavioral problems and anxiety, and parental anxiety. Based on hypotheses from a literature-built theoretical model linking demographic, clinical, family environment, and psychosocial characteristics to QoL either directly or indirectly, associations of these factors with a child's self-rated QoL were examined using a structural equation modeling approach. RESULTS: A total of 312 children (mean [SD] age, 12.2 [2.6] years; 51% boys [n = 160]) were included. Higher levels of trait anxiety and behavioral problems in children were the most important factors associated with poorer QoL (standardized path coefficients, -0.71 and -0.23, respectively). In addition, higher parent trait anxiety, younger age at diagnosis, and a disease requiring an emergency diet were associated with poorer QoL in these children. The final model fit the data closely according to conventional goodness-of-fit statistics and explained 86% of the QoL variance. CONCLUSIONS: Psychosocial factors appear to be major determinants of QoL impairment in children with IEMRDs. These factors should be addressed in clinical practice as part of the global treatment plan for a child with IEMRD. Future studies based on a longitudinal design should consider coping strategies when exploring potential predictive factors of QoL.

Galactokinase deficiency: lessons from the GalNet registry.

PURPOSE: Galactokinase (GALK1) deficiency is a rare hereditary galactose metabolism disorder. Beyond cataract, the phenotypic spectrum is questionable. Data from affected patients included in the Galactosemias Network registry were collected to better characterize the phenotype. METHODS: Observational study collecting medical data of 53 not previously reported GALK1 deficient patients from 17 centers in 11 countries from December 2014 to April 2020. RESULTS: Neonatal or childhood cataract was reported in 15 and 4 patients respectively. The occurrence of neonatal hypoglycemia and infection were comparable with the general population, whereas bleeding diathesis (8.1% versus 2.17-5.9%) and encephalopathy (3.9% versus 0.3%) were reported more often. Elevated transaminases were seen in 25.5%. Cognitive delay was reported in 5 patients. Urinary galactitol was elevated in all patients at diagnosis; five showed unexpected Gal-1-P increase. Most patients showed enzyme activities ≤1%. Eleven different genotypes were described, including six unpublished variants. The majority was homozygous for NM_000154.1:c.82C>A (p.Pro28Thr). Thirty-five patients were diagnosed following newborn screening, which was clearly beneficial. CONCLUSION: The phenotype of GALK1 deficiency may include neonatal elevation of transaminases, bleeding diathesis, and encephalopathy in addition to cataract. Potential complications beyond the neonatal period are not systematically surveyed and a better delineation is needed.

Narrative review of glycogen storage disorder type III with a focus on neuromuscular, cardiac and therapeutic aspects.

Glycogen storage disorder type III (GSDIII) is a rare inborn error of metabolism due to loss of glycogen debranching enzyme activity, causing inability to fully mobilize glycogen stores and its consequent accumulation in various tissues, notably liver, cardiac and skeletal muscle. In the pediatric population, it classically presents as hepatomegaly with or without ketotic hypoglycemia and failure to thrive. In the adult population, it should also be considered in the differential diagnosis of left ventricular hypertrophy or hypertrophic cardiomyopathy, myopathy, exercise intolerance, as well as liver cirrhosis or fibrosis with subsequent liver failure. In this review article, we first present an overview of the biochemical and clinical aspects of GSDIII. We then focus on the recent findings regarding cardiac and neuromuscular impairment associated with the disease. We review new insights into the pathophysiology and clinical picture of this disorder, including symptomatology, imaging and electrophysiology. Finally, we discuss current and upcoming treatment strategies such as gene therapy aimed at the replacement of the malfunctioning enzyme to provide a stable and long-term therapeutic option for this debilitating disease.

Health Status of French Young Patients with Inborn Errors of Metabolism with Lifelong Restricted Diet.

OBJECTIVE: To describe the health status of young patients affected by inborn errors of metabolism that require adherence to a restricted diet (IEMRDs) and to describe and compare their self- and proxy (parent)-reported quality of life (QoL) with reference values. STUDY DESIGN: A cross-sectional study was conducted in 2015-2017 in patients affected by IEMRDs (except phenylketonuria) younger than 18 years. Data collection was based on medical records, clinical examinations, parents' and children's interviews, and self-reported questionnaires. Measurements included clinical and healthcare data, child and family environment data, and self- and proxy (parent)-reported QoL. RESULTS: Of the 633 eligible participants, 578 were recruited (50.3% boys; mean age: 8.7 years); their anthropometric status did not differ from the general population. Approximately one-half of them had at least 1 complication of the disease. Their self-reported global QoL did not differ from that of the general population. However, relations with friends and leisure activities QoL domains were negatively impacted, whereas relations with medical staff, relations with parents, and self-esteem QoL domains were positively impacted. Their proxy (parent)-reported QoL was negatively impacted. CONCLUSIONS: Young patients affected by IEMRDs present a high rate of clinical complications. Although their proxy (parent)-reported QoL was negatively impacted, their self-reported QoL was variably impacted (both positively and negatively). These results may inform counseling for those who care for affected patients and their families.

Regenerative cell therapy for the treatment of hyperbilirubinemic Gunn rats with fresh and frozen human induced pluripotent stem cells-derived hepatic stem cells.

Pluripotent stem cells have been investigated as a renewable source of therapeutic hepatic cells, in order to overcome the lack of transplantable donor hepatocytes. Whereas different studies were able to correct hepatic defects in animal models, they focused on the most mature phenotype of hepatocyte-like cells (HLCs) derived from pluripotent stem cells and needed freshly prepared cells, which limits clinical applications of HLCs. Here, we report the production of hepatic stem cells (pHSCs) from human-induced pluripotent stem cells (hiPSCs) in xeno-free, feeder-free, and chemically defined conditions using as extracellular matrix a recombinant laminin instead of Matrigel, an undefined animal-derived matrix. Freshly prepared and frozen pHSCs were transplanted via splenic injection in Gunn rats, the animal model for Crigler-Najjar syndrome. Following cell transplantation and daily immunosuppression treatment, bilirubinemia was significantly decreased (around 30% decrease, P < .05) and remained stable throughout the 6-month study. The transplanted pHSCs underwent maturation in vivo to restore the deficient metabolic hepatic function (bilirubin glucuronidation by UGT1A1). In conclusion, we demonstrate for the first time the differentiation of hiPSCs into pHSCs that (a) are produced using a differentiation protocol compatible with Good Manufacturing Practices, (b) can be frozen, and (c) are sufficient to demonstrate in vivo therapeutic efficacy to significantly lower hyperbilirubinemia in a model of inherited liver disease, despite their immature phenotype. Thus, our approach provides major advances toward future clinical applications and would facilitate cell therapy manufacturing from human pluripotent stem cells.

Whole-Body Muscle Magnetic Resonance Imaging in Glycogen-Storage Disease Type III.

INTRODUCTION: The main objective of this study was to describe muscle involvement on whole-body magnetic resonance imaging scans in adults at different stages of glycogen-storage disease type III (GSDIII). METHODS: Fifteen patients, 16-59 years of age, were examined on a 3-T system. The examinations consisted of coronal and axial T1-weighted images or fat images with a Dixon technique, and were scored for 47 muscles using Mercuri's classification. Muscle changes consisted of internal bright signals of fatty replacement. RESULTS: Distribution across muscles showed predominant signal alteration in the lower limbs and postural muscles. This finding is consistent with the overall clinical presentation of GSDIII and the results of heatmap scores. Review of the MRI scans provided new information regarding recurrent muscle changes, particularly in the soleus, gastrocnemius medial head, and thoracic extensor muscles. DISCUSSION: Whole-body muscle imaging provides clinically relevant information regarding muscle involvement in GSDIII. A severity score may contribute to improved patient management. Muscle Nerve, 2019.

Progressive development of renal cysts in glycogen storage disease type I.

Glycogen storage disease type I (GSDI) is a rare metabolic disease due to glucose-6 phosphatase deficiency, characterized by fasting hypoglycemia. Patients also develop chronic kidney disease whose mechanisms are poorly understood. To decipher the process, we generated mice with a kidney-specific knockout of glucose-6 phosphatase (K.G6pc-/- mice) that exhibited the first signs of GSDI nephropathy after 6 months of G6pc deletion. We studied the natural course of renal deterioration in K.G6pc-/- mice for 18 months and observed the progressive deterioration of renal functions characterized by early tubular dysfunction and a later destruction of the glomerular filtration barrier. After 15 months, K.G6pc-/- mice developed tubular-glomerular fibrosis and podocyte injury, leading to the development of cysts and renal failure. On the basis of these findings, we were able to detect the development of cysts in 7 out of 32 GSDI patients, who developed advanced renal impairment. Of these 7 patients, 3 developed renal failure. In addition, no renal cysts were detected in six patients who showed early renal impairment. In conclusion, renal pathology in GSDI is characterized by progressive tubular dysfunction and the development of polycystic kidneys that probably leads to the development of irreversible renal failure in the late stages. Systematic observations of cyst development by kidney imaging should improve the evaluation of the disease's progression, independently of biochemical markers.

Molecular Classification of Hepatocellular Adenoma Associates With Risk Factors, Bleeding, and Malignant Transformation.

BACKGROUND & AIMS: Hepatocellular adenomas (HCAs) are benign liver tumors that can be assigned to molecular subtypes based on inactivating mutations in hepatocyte nuclear factor 1A, activating mutations in ß-catenin, or activation of inflammatory signaling pathways. We aimed to update the classification system for HCA and associate the subtypes with disease risk factors and complications. METHODS: We analyzed expression levels of 20 genes and sequenced exon regions of 8 genes (HNF1A, IL6ST, CTNNB1, FRK, STAT3, GNAS, JAK1, and TERT) in 607 samples of 533 HCAs from 411 patients, collected from 28 centers mainly in France from 2000 and 2014. We performed gene expression profile, RNA sequence, whole-exome and genome sequence, and immunohistochemical analyses of select samples. Molecular data were associated with risk factors, histopathology, bleeding, and malignant transformation. RESULTS: Symptomatic bleeding occurred in 14% of the patients (85% of cases were female, median age, 38 years); 7% of the nodules were borderline between HCA and hepatocellular carcinoma, and 3% of patients developed hepatocellular carcinoma from HCA. Based on molecular features, we classified HCA into 8 subgroups. One new subgroup, composed of previously unclassified HCA, represented 4% of HCAs overall and was associated with obesity and bleeding. These tumors were characterized by activation of sonic hedgehog signaling, due to focal deletions that fuse the promoter of INHBE with GLI1. Analysis of genetic heterogeneity among multiple HCAs, from different patients, revealed a molecular subtype field effect; multiple tumors had different mutations that deregulated similar pathways. Specific molecular subtypes of HCA associated with various HCA risk factors, including imbalances in estrogen or androgen hormones. Specific molecular subgroup of HCA with ß-catenin and sonic hedgehog activation associated with malignant transformation and bleeding, respectively. CONCLUSIONS: Using sequencing and gene expression analyses, we identified a subgroup of HCA characterized by fusion of the INHBE and GLI1 genes and activation of sonic hedgehog pathway. Molecular subtypes of HCAs associated with different patients' risk factors for HCA, disease progression, and pathology features of tumors. This classification system might be used to select treatment strategies for patients with HCA.

Dental and periodontal manifestations of glycogen storage diseases: a case series of 60 patients.

Glycogen storage diseases (GSDs) are rare genetic disorders of glycogen metabolism where the liver, kidneys, respiratory and cardiac muscles, as well as the immune and skeletal systems can be affected. Oral manifestations can also be present, but the specificity and frequency of these manifestations in the different forms of GSD are unknown. Analysis of a case series of 60 patients presenting four types of GSD (Ia, Ib, III, and IX) showed that the different types of GSDs have common and specific oral manifestations. In none of the GSD types studied, the prevalence of caries was higher than in the general population, especially in patients benefiting from current nutritional therapy, while in all GSD types the prevalence of delayed tooth eruption, agenesis, and tooth shape abnormalities was increased compared to the general population. Severe periodontitis prevalence was increased in patients with GSD Ib and neutropenia. Our results show that GSDs have oral manifestations and suggest some specificity depending on the type of GSDs.

Long term longitudinal study of muscle function in patients with glycogen storage disease type IIIa.

Glycogen storage disease type III (GSDIII) is an autosomal recessive disorder caused by mutations in the AGL gene coding for the glycogen debranching enzyme. Current therapy is based on dietary adaptations but new preclinical therapies are emerging. The identification of outcome measures which are sensitive to disease progression becomes critical to assess the efficacy of new treatments in upcoming clinical trials. In order to prepare future longitudinal studies or therapeutic trials with large cohorts, information about disease progression is required. In this study we present preliminary longitudinal data of Motor Function Measure (MFM), timed tests, Purdue pegboard test, and handgrip strength collected over 5 to 9years of follow-up in 13 patients with GSDIII aged between 13 and 56years old. Follow-up for nine of the 13 patients was up to 9years. Similarly to our previous cross-sectional retrospective study, handgrip strength significantly decreased with age in patients older than 37years. MFM scores started to decline after the age of 35. The Purdue pegboard score also significantly reduced with increasing age (from 13years of age) but with large inter-visit variations. The time to stand up from a chair or to climb 4 stairs increased dramatically in some but not all patients older than 30years old. In conclusion, this preliminary longitudinal study suggests that MFM and handgrip strength are the most sensitive muscle function outcome measures in GSDIII patients from the end of their third decade. Sensitive muscle outcome measures remain to be identified in younger GSDIII patients but is challenging as muscle symptoms remain discrete and often present as accumulated fatigue.

International clinical guideline for the management of classical galactosemia: diagnosis, treatment, and follow-up.

Classical galactosemia (CG) is an inborn error of galactose metabolism. Evidence-based guidelines for the treatment and follow-up of CG are currently lacking, and treatment and follow-up have been demonstrated to vary worldwide. To provide patients around the world the same state-of-the-art in care, members of The Galactosemia Network (GalNet) developed an evidence-based and internationally applicable guideline for the diagnosis, treatment, and follow-up of CG. The guideline was developed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. A systematic review of the literature was performed, after key questions were formulated during an initial GalNet meeting. The first author and one of the working group experts conducted data-extraction. All experts were involved in data-extraction. Quality of the body of evidence was evaluated and recommendations were formulated. Whenever possible recommendations were evidence-based, if not they were based on expert opinion. Consensus was reached by multiple conference calls, consensus rounds via e-mail and a final consensus meeting. Recommendations addressing diagnosis, dietary treatment, biochemical monitoring, and follow-up of clinical complications were formulated. For all recommendations but one, full consensus was reached. A 93 % consensus was reached on the recommendation addressing age at start of bone density screening. During the development of this guideline, gaps of knowledge were identified in most fields of interest, foremost in the fields of treatment and follow-up.

Peripheral neuropathy in glycogen storage disease type III: Fact or myth?

INTRODUCTION: The aim of this study was to assess whether peripheral neuropathy is a feature of glycogen storage disease type IIIa (GSD IIIa) in adult patients. METHODS: Medical records of a cohort of adult GSD IIIa patients who underwent electromyography (EMG) and nerve conduction studies (NCS) were reviewed, and the results were correlated with physical examination findings. RESULTS: Sixteen patients underwent EMG and NCS; 4 complained of exercise intolerance, 1 of foot paresthesia, and 11 of muscle weakness (3 proximal, 8 distal). None of the patients had sensory deficits on clinical examination. All motor and sensory conduction velocities and sensory amplitudes were within reference ranges. EMG showed myopathic motor unit potentials in 15 of the 16 patients. CONCLUSIONS: Based on the clinical examination and the NCS and EMG results, we did not identify any peripheral nerve involvement in our adult patients diagnosed with GSD III.

Glycogen storage disease type III: diagnosis, genotype, management, clinical course and outcome.

Glycogen storage disease type III (GSDIII) is a rare disorder of glycogenolysis due to AGL gene mutations, causing glycogen debranching enzyme deficiency and storage of limited dextrin. Patients with GSDIIIa show involvement of liver and cardiac/skeletal muscle, whereas GSDIIIb patients display only liver symptoms and signs. The International Study on Glycogen Storage Disease (ISGSDIII) is a descriptive retrospective, international, multi-centre cohort study of diagnosis, genotype, management, clinical course and outcome of 175 patients from 147 families (86 % GSDIIIa; 14 % GSDIIIb), with follow-up into adulthood in 91 patients. In total 58 AGL mutations (non-missense mutations were overrepresented and 21 novel mutations were observed) were identified in 76 families. GSDIII patients first presented before the age of 1.5 years, hepatomegaly was the most common presenting clinical sign. Dietary management was very diverse and included frequent meals, uncooked cornstarch and continuous gastric drip feeding. Chronic complications involved the liver (hepatic cirrhosis, adenoma(s), and/or hepatocellular carcinoma in 11 %), heart (cardiac involvement and cardiomyopathy, in 58 % and 15 %, respectively, generally presenting in early childhood), and muscle (pain in 34 %). Type 2 diabetes mellitus was diagnosed in eight out of 91 adult patients (9 %). In adult patients no significant correlation was detected between (non-) missense AGL genotypes and hepatic, cardiac or muscular complications. This study demonstrates heterogeneity in a large cohort of ageing GSDIII patients. An international GSD patient registry is warranted to prospectively define the clinical course, heterogeneity and the effect of different dietary interventions in patients with GSDIII.

Confined blood chimerism in a monochorionic dizygotic sex discordant twin pregnancy conceived after induced ovulation.

BACKGROUND: Monochorionic twins are generally considered as a monozygotic twin pregnancy. However, several cases of monochorial dizygotic twin pregnancies have been reported. CASE REPORT: We report on a rare case of monochorionic dizygotic twin pregnancy conceived after induced ovulation in a 32-year-old woman. The diagnosis was made on morphological ultrasound examination at 18+4 weeks of gestation, showing two fetuses with discordant sex. The amniocentesis was declined by the patient. RESULTS: The monochorionic status was confirmed after a histopathalogical study of the placenta. At delivery, both a phenotypically normal boy and a phenotypically normal girl without sexual abnormality were observed. This analysis also revealed the presence of vascular anastomoses between both fetal circulations. Postnatal cytogenetic analyses indicated the presence of a chimerism in peripheral blood lymphocytes. This chimerism was not observed in cells obtained from a buccal swab. Molecular determination of zygosity confirmed the existence of the confined peripheral blood chimerism with the presence of four parental alleles. CONCLUSION: We report on a case of monochorionic dizygotic twin pregnancy. This observation underlies the need to carefully assess twin pregnancies, especially when obtained after assisted reproductive technology.