Pancreatitis as a Main Consequence of APOC2-Related Hypertriglyceridemia: The Role of Nonsense and Frameshift Variants

APOC2-related hypertriglyceridemia occurs due to biallelic variants of this gene. Here, genotype-phenotype architecture of all pathogenic APOC2 variants is investigated among heterozygous and homozygous individuals. Clinical heterogeneity of various types of the variants is also described, and pancr...

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Main Authors: Bahareh Rabbani, Mohadeseh Aghli Moghadam, Shiva Esmaeili, Amirhassan Rabbani, Bahman Akbari, Nejat Mahdieh
Format: Article
Language:English
Published: Wiley 2024-01-01
Series:International Journal of Genomics
Online Access:http://dx.doi.org/10.1155/2024/6653857
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author Bahareh Rabbani
Mohadeseh Aghli Moghadam
Shiva Esmaeili
Amirhassan Rabbani
Bahman Akbari
Nejat Mahdieh
author_facet Bahareh Rabbani
Mohadeseh Aghli Moghadam
Shiva Esmaeili
Amirhassan Rabbani
Bahman Akbari
Nejat Mahdieh
author_sort Bahareh Rabbani
collection DOAJ
description APOC2-related hypertriglyceridemia occurs due to biallelic variants of this gene. Here, genotype-phenotype architecture of all pathogenic APOC2 variants is investigated among heterozygous and homozygous individuals. Clinical heterogeneity of various types of the variants is also described, and pancreatitis in more than half of homozygotes carrying chain-termination variants is highlighted as well. For this study, patients were selected who had a plasma triglyceride level above 250 mg/dL. The coding and intronic regions of the APOC2 gene were amplified using the Sanger sequencing to investigate the presence of variants. The genotypes, lipid profiles, and detailed clinical features were documented for all APOC2-related patients and heterozygous individuals. Pathogenicity of the variants was predicted and categorized using available bioinformatics tools such as MutationTaster and PolyPhen-2 and ACMG criteria. MetaDome and Phyre2 were applied for structural and functional in silico analyses. 40% (12 out of 30) of APOC2 variants were chain-termination (nonsense and frameshift) variants. These types of variants were determined in 60.53% of patients. 55% of these patients showed pancreatitis followed by lipemia retinalis (29%), abdominal pain (24%), hepatosplenomegaly (24%), and xanthomas (18%). The mean age of onset was about 22 years old. In at least 50% of 38 homozygous individuals, the TG level was more than 2000 mg/dL. More than 25% of heterozygous individuals showed at least one symptom. Pancreatitis and a severe form of HTG were found in 5 and 2% of heterozygous individuals, respectively. The main clinical features of APOC2-related hypertriglyceridemia include pancreatitis, lipemia retinalis, abdominal pain, hepatosplenomegaly, and xanthomas. Nonsense and frameshift homozygous variants usually lead to a severe form of hypertriglyceridemia. Pancreatitis is one of the main consequences of these types of mutations; thus, it is important to consider this point when evaluating asymptomatic individuals. Heterozygous individuals may become symptomatic due to the role of unknown modifying agent including environmental genetic factors.
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spelling doaj-art-6e282e14d97c48ae8d8b29e416c2052c2025-08-20T02:06:31ZengWileyInternational Journal of Genomics2314-43782024-01-01202410.1155/2024/6653857Pancreatitis as a Main Consequence of APOC2-Related Hypertriglyceridemia: The Role of Nonsense and Frameshift VariantsBahareh Rabbani0Mohadeseh Aghli Moghadam1Shiva Esmaeili2Amirhassan Rabbani3Bahman Akbari4Nejat Mahdieh5Growth and Development Research CenterDepartment of GeneticsGrowth and Development Research CenterTaleghani HospitalDepartment of Medical BiotechnologyGrowth and Development Research CenterAPOC2-related hypertriglyceridemia occurs due to biallelic variants of this gene. Here, genotype-phenotype architecture of all pathogenic APOC2 variants is investigated among heterozygous and homozygous individuals. Clinical heterogeneity of various types of the variants is also described, and pancreatitis in more than half of homozygotes carrying chain-termination variants is highlighted as well. For this study, patients were selected who had a plasma triglyceride level above 250 mg/dL. The coding and intronic regions of the APOC2 gene were amplified using the Sanger sequencing to investigate the presence of variants. The genotypes, lipid profiles, and detailed clinical features were documented for all APOC2-related patients and heterozygous individuals. Pathogenicity of the variants was predicted and categorized using available bioinformatics tools such as MutationTaster and PolyPhen-2 and ACMG criteria. MetaDome and Phyre2 were applied for structural and functional in silico analyses. 40% (12 out of 30) of APOC2 variants were chain-termination (nonsense and frameshift) variants. These types of variants were determined in 60.53% of patients. 55% of these patients showed pancreatitis followed by lipemia retinalis (29%), abdominal pain (24%), hepatosplenomegaly (24%), and xanthomas (18%). The mean age of onset was about 22 years old. In at least 50% of 38 homozygous individuals, the TG level was more than 2000 mg/dL. More than 25% of heterozygous individuals showed at least one symptom. Pancreatitis and a severe form of HTG were found in 5 and 2% of heterozygous individuals, respectively. The main clinical features of APOC2-related hypertriglyceridemia include pancreatitis, lipemia retinalis, abdominal pain, hepatosplenomegaly, and xanthomas. Nonsense and frameshift homozygous variants usually lead to a severe form of hypertriglyceridemia. Pancreatitis is one of the main consequences of these types of mutations; thus, it is important to consider this point when evaluating asymptomatic individuals. Heterozygous individuals may become symptomatic due to the role of unknown modifying agent including environmental genetic factors.http://dx.doi.org/10.1155/2024/6653857
spellingShingle Bahareh Rabbani
Mohadeseh Aghli Moghadam
Shiva Esmaeili
Amirhassan Rabbani
Bahman Akbari
Nejat Mahdieh
Pancreatitis as a Main Consequence of APOC2-Related Hypertriglyceridemia: The Role of Nonsense and Frameshift Variants
International Journal of Genomics
title Pancreatitis as a Main Consequence of APOC2-Related Hypertriglyceridemia: The Role of Nonsense and Frameshift Variants
title_full Pancreatitis as a Main Consequence of APOC2-Related Hypertriglyceridemia: The Role of Nonsense and Frameshift Variants
title_fullStr Pancreatitis as a Main Consequence of APOC2-Related Hypertriglyceridemia: The Role of Nonsense and Frameshift Variants
title_full_unstemmed Pancreatitis as a Main Consequence of APOC2-Related Hypertriglyceridemia: The Role of Nonsense and Frameshift Variants
title_short Pancreatitis as a Main Consequence of APOC2-Related Hypertriglyceridemia: The Role of Nonsense and Frameshift Variants
title_sort pancreatitis as a main consequence of apoc2 related hypertriglyceridemia the role of nonsense and frameshift variants
url http://dx.doi.org/10.1155/2024/6653857
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