Progressive Myoclonus Epilepsy in Congenital Generalized Lipodystrophy type 2: Report of 3 cases and literature review

Progressive Myoclonus Epilepsy: A Scoping Review of Diagnostic, Phenotypic and Therapeutic Advances

The progressive myoclonus epilepsies (PME) are a diverse group of disorders that feature both myoclonus and seizures that worsen gradually over a variable timeframe. While each of the disorders is individually rare, they collectively make up a non-trivial portion of the complex epilepsy and myoclonus cases that are seen in tertiary care centers. The last decade has seen substantial progress in our understanding of the pathophysiology, diagnosis, prognosis, and, in select disorders, therapies of these diseases. In this scoping review, we examine English language publications from the past decade that address diagnostic, phenotypic, and therapeutic advances in all PMEs. We then highlight the major lessons that have been learned and point out avenues for future investigation that seem promising.

Features of BSCL2 related congenital generalized lipodystrophy in China: long-term follow-up of three patients and literature review

OBJECTIVES

Congenital generalized lipodystrophy (CGL) is a group of rare autosomal inherited diseases characterized by a widespread loss of adipose tissue. The main purpose of this study was to evaluate the features of Chinese patients with CGL2.

METHODS

Three patients diagnosed with CGL2 from our center were reviewed. Data on clinical features, results of laboratory analyses, and previous treatments were retrospectively collected. This study also reviewed studies that reported patients diagnosed with CGL2 in the last 30 years.

RESULTS

All patients presented a lack of subcutaneous fat, hypertriglyceridemia, reversed triangular faces, acanthosis nigricans, and hepatomegaly within the first six months of life. All three patients developed splenomegaly, and mental retardation in later life. Dietary control dramatically lowered triglyceride levels in all patients. One patient presented with diabetes mellitus at 1 year-old. Although combined therapy with low fat diet and metformin maintained normal levels of blood lipid and glucose, this patient developed hypertrophic cardiomyopathy at the age of three. By a literature review on all Chinese cases with CGL2, it is known that classic manifestations such as hypertriglyceridemia, hepatomegaly and diabetes mellitus can occur shortly after birth, and early diagnosis and treatment can improve quality of life. In this cohort, the most frequent variations are c.782dupG and c.974dup in the BSCL2 gene. However, the same genotype may have different clinical phenotypes in patients with CGL2.

CONCLUSIONS

This study not only described the clinical and genetic features of three patients with CGL2 in China, but also reviewed literature about CGL2 around the world.

Hereditary severe insulin resistance syndrome: Pathogenesis, pathophysiology, and clinical management

Severe insulin resistance has been linked to some of the most globally prevalent disorders, such as diabetes mellitus, nonalcoholic fatty liver disease, polycystic ovarian syndrome, and hypertension. Hereditary severe insulin resistance syndrome (H-SIRS) is a rare disorder classified into four principal categories: primary insulin receptor defects, lipodystrophies, complex syndromes, and obesity-related H-SIRS. Genes such as INSR, AKT2, TBC1D4, AGPAT2, BSCL2, CAV1, PTRF, LMNA, PPARG, PLIN1, CIDEC, LIPE, PCYT1A, MC4R, LEP, POMC, SH2B1, RECQL2, RECQL3, ALMS1, PCNT, ZMPSTE24, PIK3R1, and POLD1 have been linked to H-SIRS. Its clinical features include insulin resistance, hyperglycemia, hyperandrogenism, severe dyslipidemia, fatty liver, abnormal topography of adipose tissue, and low serum leptin and adiponectin levels. Diagnosis of H-SIRS is based on the presence of typical clinical features associated with the various H-SIRS forms and the identification of mutations in H-SIRS-linked genes by genetic testing. Diet therapy, insulin sensitization, exogenous insulin therapy, and leptin replacement therapy have widely been adopted to manage H-SIRS. The rarity of H-SIRS, its highly variable clinical presentation, refusal to be tested for genetic mutations by patients' family members who are not severely sick, unavailability of genetic testing, and testing expenses contribute to the delayed or underdiagnoses of H-SIRS. Early diagnosis facilitates early management of the condition, which results in improved glycemic control and delayed onset of diabetes and other complications related to severe insulin resistance. The use of updated genetic sequencing technologies is recommended, and long-term studies are required for genotype-phenotype differentiation and formulation of diagnostic and treatment protocols.

Celia's Encephalopathy (BSCL2-Gene-Related): Current Understanding

Seipin, encoded by the BSCL2 gene, is a protein that in humans is expressed mainly in the central nervous system. Uniquely, certain variants in BSCL2 can cause both generalized congenital lipodystrophy type 2, upper and/or lower motor neuron diseases, or progressive encephalopathy, with a poor prognosis during childhood. The latter, Celia's encephalopathy, which may or may not be associated with generalized lipodystrophy, is caused by the c.985C >T variant. This cytosine to thymine transition creates a cryptic splicing zone that leads to intronization of exon 7, resulting in an aberrant form of seipin, Celia seipin. It has been proposed that the accumulation of this protein, both in the endoplasmic reticulum and in the nucleus of neurons, might be the pathogenetic mechanism of this neurodegenerative condition. In recent years, other variants in BSCL2 associated with generalized lipodystrophy and progressive epileptic encephalopathy have been reported. Interestingly, most of these variants could also lead to the loss of exon 7. In this review, we analyzed the molecular bases of Celia's encephalopathy and its pathogenic mechanisms, the clinical features of the different variants, and a therapeutic approach in order to slow down the progression of this fatal neurological disorder.

Metreleptin for the treatment of progressive encephalopathy with/without lipodystrophy (PELD) in a child with progressive myoclonic epilepsy: a case report

BACKGROUND

A number of genetic syndromes associated with variants in the BSCL2/seipin gene have been identified. Variants that cause skipping of exon 7 are associated with progressive encephalopathy with/without lipodystrophy (PELD), which is characterized by the development of progressive myoclonic epilepsy at a young age, severe progressive neurological impairment, and early death, often in childhood. Because the genetic basis of PELD is similar to that of congenital lipodystrophy type 2, we hypothesized that a patient with PELD may respond to treatments approved for other congenital lipodystrophic syndromes.

CASE PRESENTATION

We describe a 5-year-old boy with an extremely rare phenotype involving severe progressive myoclonic epilepsy who received metreleptin (a recombinant analogue of leptin) to control metabolic abnormalities. At the age of two, he had no subcutaneous adipose tissue, with hypertriglyceridemia, hypertransaminasemia and hepatic steatosis. He also had a moderate psychomotor delay and generalized tonic seizures. At 4 years, he had insulin resistance, hypercholesterolemia, hypertriglyceridemia, mild hepatosplenomegaly and mild hepatic steatosis; he began a hypolipidemic diet. Severe psychomotor delay and myoclonic/myoclonic atonic seizures with absences was evident. At 5 years of age, metreleptin 0.06 mg/kg/day was initiated; after 2 months, the patient's lipid profile improved and insulin resistance resolved. After 1 year of treatment, hepatic steatosis improved and abdominal ultrasound showed only mild hepatomegaly. Seizure frequency decreased but was not eliminated during metreleptin therapy.

CONCLUSIONS

Metreleptin may be used to control metabolic disturbances and may lead to better seizure control in children with PELD.

Focus on progressive myoclonic epilepsy in Berardinelli-Seip syndrome

INTRODUCTION

Berardinelli-Seip syndrome or congenital generalized lipodystrophy type 2 is a rare genetic disorder characterized by selective loss of subcutaneous adipose tissue associated with peripheral insulin resistance and its complications. Nonprogressive mental retardation, dystonia, ataxia, and pyramidal signs are commonly present, whereas epilepsy has only occasionally been observed.

CASE REPORT

We report the case of two sisters, 11 and 18 years old respectively, with an overlapping clinical phenotype compatible with Berardinelli-Seip syndrome and progressive myoclonic epilepsy. Molecular analysis identified an autosomal recessive c.1048C > t;(p(Arg350*)) pathogenic mutation of exon 8 of the BSCL2 gene, which was present in a homozygous state in both patients.

CONCLUSIONS

Our paper contributes to further delineate a complex phenotype associated with BSCL2 mutation, underlining how seipin has a central and partially still unknown role that goes beyond adipose tissue metabolism, with a prominent involvement in central nervous system pathology.

Genotype-phenotype correlations of Berardinelli-Seip congenital lipodystrophy and novel candidate genes prediction

BACKGROUND

Berardinelli-Seip congenital lipodystrophy (BSCL) is a heterogeneous autosomal recessive disorder characterized by an almost total lack of adipose tissue in the body. Mutations in the AGPAT2, BSCL2, CAV1 and PTRF genes define I-IV subtype of BSLC respectively and clinical data indicate that new causative genes remain to be discovered. Here, we retrieved 341 cases from 60 BSCL-related studies worldwide and aimed to explore genotype-phenotype correlations based on mutations of AGPAT2 and BSCL2 genes from 251 cases. We also inferred new candidate genes for BSCL through protein-protein interaction and phenotype-similarity.

RESULTS

Analysis results show that BSCL type II with earlier age of onset of diabetes mellitus, higher risk to suffer from premature death and mental retardation, is a more severe disorder than BSCL type I, but BSCL type I patients are more likely to have bone cysts. In BSCL type I, females are at higher risk of developing diabetes mellitus and acanthosis nigricans than males, while in BSCL type II, males suffer from diabetes mellitus earlier than females. In addition, some significant correlations among BSCL-related phenotypes were identified. New candidate genes prediction through protein-protein interaction and phenotype-similarity was conducted and we found that CAV3, EBP, SNAP29, HK1, CHRM3, OBSL1 and DNAJC13 genes could be the pathogenic factors for BSCL. Particularly, CAV3 and EBP could be high-priority candidate genes contributing to pathogenesis of BSCL.

CONCLUSIONS

Our study largely enhances the current knowledge of phenotypic and genotypic heterogeneity of BSCL and promotes the more comprehensive understanding of pathogenic mechanisms for BSCL.

Advances in genetic testing and optimization of clinical management in children and adults with epilepsy

Introduction: Epileptic disorders are a heterogeneous group of medical conditions with epilepsy as the common denominator. Genetic causes, electro-clinical features, and management significantly vary according to the specific condition.Areas covered: Relevant diagnostic advances have been achieved thanks to the advent of Next Generation Sequencing (NGS)-based molecular techniques. These revolutionary tools allow to sequence all coding (whole exome sequencing, WES) and non-coding (whole genome sequencing, WGS) regions of human genome, with a potentially huge impact on patient care and scientific research.Expert opinion: The application of these tests in children and adults with epilepsy has led to the identification of new causative genes, widening the knowledge on the pathophysiology of epilepsy and resulting in therapeutic implications. This review will explore the most recent advancements in genetic testing and provide up-to-date approaches for the choice of the correct test in patients with epilepsy.

Medical management of a child with congenital generalized lipodystrophy accompanied with progressive myoclonic epilepsy: A case report

RATIONALE

Congenital generalized lipodystrophy (CGL) is a rare autosomal recessive hereditary disease. It is associated with metabolic complications and epilepsy is rare.

PATIENT CONCERNS AND DIAGNOSES

One child with BSCL2 mutation and CGL accompanied by progressive myoclonic epilepsyDiagnosis: He was diagnosed with epilepsy, CGL, and severe malnutrition.

INTERVENTIONS

He was treated with sodium valproate, baclofen, aripiprazole, benzhexol, and lamotrigine for epilepsy.

OUTCOMES

After 16 days of medical treatment for epilepsy, the disease was improved and the child was discharged with gastric tube inserted for the management of malnutrition.

LESSONS

CGL and progressive myoclonic epilepsy is rare, and the epilepsy is partially refractory to treatments. In this particular case, the nutritional status was compromised as a complication of progressive myoclonic epilepsy and had to be managed.

Celia's encephalopathy and c.974dupG in BSCL2 gene: a hidden change in a known variant

Celia's encephalopathy (progressive encephalopathy with/without lipodystrophy (PELD)) is a childhood neurodegenerative disorder with a fatal prognosis before the age of 10, due to the variant c.985C>T in the BSCL2 gene that causes a cryptic splicing site leading to skipping of exon 7. For years, different authors have reported cases of congenital generalized lipodystrophy due to the variant c.974dupG in BSCL2 associated with neurological manifestations of variable severity, although some of them clearly superimposable to PELD. To identify the molecular mechanisms responsible for these neurological alterations in two patients with c.974dupG. Clinical characterization, biochemistry, and neuroimaging studies of two girls carrying this variant. In silico analysis, PCR amplification, and BSCL2 cDNA sequencing. BSCL2-201 transcript expression, which lacks exon 7, by qPCR in fibroblasts from the index case, from a healthy child as a control and from two patients with PELD, and in leukocytes from the index case and her parents. One with a severe encephalopathy including a picture of intellectual deficiency, severe language impairment, myoclonic epilepsy, and lipodystrophy as described in PELD, dying at 9 years and 9 months of age. The other 2-year-old patient showed incipient signs of neurological involvement. In silico and cDNA sequencing studies showed that variant c.974dupG gives rise to skipping of exon 7. The expression of BSCL2-201 in fibroblasts was significantly higher in the index case than in the healthy child, although less than in the case with homozygous PELD due to c.985C>T variant. The expression of this transcript was approximately half in the healthy carrier parents of this patient. The c.974dupG variant leads to the skipping of exon 7 of the BSCL2 gene and is responsible for a variant of Celia's encephalopathy, with variable phenotypic expression.

Clinical outcome in a series of pediatric patients with congenital generalized lipodystrophies treated with dietary therapy

BACKGROUND

Congenital generalized lipodystrophy (CGL) produces clinical features with severe metabolic consequences. Research has focused on measuring the response to the drugs. Nevertheless, there are no studies on the response to dietary therapy. The aim of this study was to show the clinical response to early nutritional intervention to modify or reverse metabolic effects in pediatric patients with CGL.

METHODS

A retrospective study was conducted on patients with CGL followed up between January 2003 and June 2017. After diagnosis, patients were indicated a diet with a total calorie intake according to the reference daily intake (RDI), without fast sugars. Clinical feature and laboratory tests (insulin, glucose, A1C, lipid panel, liver and kidney function tests), and complementary studies (abdominal ultrasonography, echocardiogram), at the first visit and during follow-up were recorded. Statistics, version 10, was used for analysis.

RESULTS

Eight patients were included. The median age at the first visit was 1.1 years (range, 0.28-9.9 years) and the median time of follow-up was 3.9 years (range, 0.4-9.47 years). The median initial triglyceride level was 516 mg/dL (range, 327-3590 mg/dL) p=0.014; median low-density lipoprotein (LDL) was 157 mg/dL (range, 94-370 mg/dL) p=0.03; median glycemia was 84 mg/dL (range, 63-126 mg/dL) p=0.02; median insulin was 28.84 µUI/mL (range, 3.9-116); median homeostatic model assessment-insulin resistance (HOMA-IR) was 5.3 (range, 1.21-23.2). After 3-6 months of diet, the median percentage of triglyceride decrease was 79.5% (range, 47-97%), LDL 44% (range, 20.5-59%), glycemia 8.8% (range, 0-53.1%), insulin 67.8% (range, 0-92.8%) p=0.02 and HOMA-IR was 81.5% (range, 50-98%) p=0.05. As of the last follow-up visit, in none of the patients, liver ultrasonography or echocardiogram had deteriorated.

CONCLUSIONS

In these pediatric patients with CGL, a diet adjusted to RDI with restriction of fast sugars led to a marked improvement in metabolic parameters.