Clinical observations and treatment of pediatric homozygous familial hypercholesterolemia due to a low-density lipoprotein receptor defect

Risk Assessment and Clinical Management of Children and Adolescents with Heterozygous Familial Hypercholesterolaemia. A Position Paper of the Associations of Preventive Pediatrics of Serbia, Mighty Medic and International Lipid Expert Panel

Heterozygous familial hypercholesterolaemia (FH) is among the most common genetic metabolic lipid disorders characterised by elevated low-density lipoprotein cholesterol (LDL-C) levels from birth and a significantly higher risk of developing premature atherosclerotic cardiovascular disease. The majority of the current pediatric guidelines for clinical management of children and adolescents with FH does not consider the impact of genetic variations as well as characteristics of vascular phenotype as assessed by recently developed non-invasive imaging techniques. We propose a combined integrated approach of cardiovascular (CV) risk assessment and clinical management of children with FH incorporating current risk assessment profile (LDL-C levels, traditional CV risk factors and familial history) with genetic and non-invasive vascular phenotyping. Based on the existing data on vascular phenotype status, this panel recommends that all children with FH and cIMT ≥0.5 mm should receive lipid lowering therapy irrespective of the presence of CV risk factors, family history and/or LDL-C levels Those children with FH and cIMT ≥0.4 mm should be carefully monitored to initiate lipid lowering management in the most suitable time. Likewise, all genetically confirmed children with FH and LDL-C levels ≥4.1 mmol/L (160 mg/dL), should be treated with lifestyle changes and LLT irrespective of the cIMT, presence of additional RF or family history of CHD.

Development and Clinical Applications of Antisense Oligonucleotide Gapmers

DNA-like molecules called antisense oligonucleotides have opened new treatment possibilities for genetic diseases by offering a method of regulating gene expression. Antisense oligonucleotides are often used to suppress the expression of mutated genes which may interfere with essential downstream pathways. Since antisense oligonucleotides have been introduced for clinical use, different chemistries have been developed to further improve efficacy, potency, and safety. One such chemistry is a chimeric structure of a central block of deoxyribonucleotides flanked by sequences of modified nucleotides. Referred to as a gapmer, this chemistry produced promising results in the treatment of genetic diseases. Mipomersen and inotersen are examples of recent FDA-approved antisense oligonucleotide gapmers used for the treatment of familial hypercholesterolemia and hereditary transthyretin amyloidosis, respectively. In addition, volanesorsen was conditionally approved in the EU for the treatment of adult patients with familial chylomicronemia syndrome (FCS) in 2019. Many others are being tested in clinical trials or under preclinical development. This chapter will cover the development of mipomersen and inotersen in clinical trials, along with advancement in gapmer treatments for cancer, triglyceride-elevating genetic diseases, Huntington's disease, myotonic dystrophy, and prion diseases.

Ischemic necrosis of the digits and hyperlipidemia associated with atherosclerosis in a Miniature American Shepherd

CASE DESCRIPTION A 2.5-year-old 12-kg (26.4-lb) castrated male Miniature American Shepherd was referred because of a 3-week history of a localized crusted skin lesion on the digital pad of digit 3 of the right hind limb. CLINICAL FINDINGS Skin lesions were noted on the digital pads of the right hind limb. Serum biochemical analyses indicated severe hypercholesterolemia and hypertriglyceridemia. Ultrasonography of the terminal portion of the aorta and other major arterial vessels revealed substantial arteriosclerotic change. TREATMENT AND OUTCOME Medical treatments included administration of atorvastatin calcium, a low-fat diet, and omega-3 fatty acids to reduce serum lipids concentration; clopidogrel to prevent thrombosis; pentoxifylline to improve microcirculatory blood flow; clomipramine hydrochloride and trazodone hydrochloride to help with the behavioral problems; and gabapentin to help with pain management and behavioral problems. Surgical management included amputation of the initial digit involved, then eventually the entire initial limb involved. The response to treatment was poor, and euthanasia was elected. Postmortem findings revealed severe, widespread, and chronic intimal atherosclerosis; mild, widespread, and degenerative changes in the cerebral cortex; and edema and vascular congestion in the meninges. CLINICAL RELEVANCE To the authors' knowledge, this was the first report of skin necrosis secondary to atherosclerosis in a dog. Although the incidence of atherosclerosis has been considered very low in dogs, it should be investigated in dogs with severe hyperlipidemia. Primary hyperlipidemia has not been previously described in Miniature American Shepherd dogs but was the suspected underlying metabolic disorder.

Clinical features and genetic analysis of childhood sitosterolemia: Two case reports and literature review

RATIONALE

Sitosterolemia is a rare autosomal recessive disorder of dyslipidemia due to mutations of genes ABCG5 and ABCG8, leading to highly elevated plasma levels of plant sterols and expanded body pools of cholesterol.

PATIENT CONCERNS

We present a 9-year-old and a 7-year-old Chinese boy with hypercholesterolemia and xanthomas of sitosterolemia due to ABCG5 gene mutations. We also make a literature review of another 30 sitosterolemic children cases that have been reported with virulence ABCG5 gene mutations.

DIAGNOSIS

We took peripheral blood samples from 2 patients and their parents to conduct genetic analysis by next-generation sequencing (NGS) technologies.

INTERVENTIONS

The 2 patients received dietary modifications without pharmaceuticals treatment.

OUTCOMES

A c.1166G>A (Arg389His) homozygosis mutation in exon 9 was observed in case 1, whereas a c.751C>T (Gln251*) homozygosis mutation in exon 6 was found in case 2. Literature review found another 30 pediatric cases with sitosterolemia due to ABCG5 gene mutation. The lipid profile was normalized and xanthomas got smaller with combined therapy of a combined low-cholesterol and low-phytosterols diet.

LESSONS

These suggested that in patients (especially Asian patients) with multiple xanthomas, severe hypercholesterolemia, or elevated low-density lipoprotein-cholesterol, sitosterolemia should be considered in the differential diagnosis. Early diagnosis is important, and restriction of both cholesterol and phytosterols diet should suggested for these patients.

The Hyperlipidemia Caused by Overuse of Glucocorticoid after Liver Transplantation and the Immune Adjustment Strategy

The overuse of glucocorticoid may cause the metabolic disorders affecting the long term outcome of liver transplantation. This study aims to investigate the immune adjustment strategy by decreasing use of glucocorticoid after liver transplantation. The follow-up study was carried out on liver function and lipid metabolism. This study included adult recipients of liver transplantation. There were 3 groups according to their use of glucocorticoid: long term (>3 months, n = 18), short term (<3 months, n = 20), and control group (no use of glucocorticoid, radical hepatic resection, n = 22). The laboratory results of liver function (AST/ALT ratio) and serum lipid were compared 6 months after liver transplantation. AST/ALT ratio, the marker of liver function, showed no significant difference between long and short term group (P > 0.05). The acute rejection had no significant difference between short and long term groups, while TG, HDL, LDL, and glucose showed significant change in the long term group (P < 0.05). At 6 months after liver transplantation, the long term group showed higher metabolic disorders (P < 0.05). The proper immune adjustment strategy should be made to avoid overuse of glucocorticoid. It can decrease hyperlipidemia and other metabolic disorders after liver transplantation without increasing the acute rejection or liver function damage.