Related Experiment Video
Updated: Jun 17, 2025
00:06
In Vivo Functional Study of Disease-associated Rare Human Variants Using Drosophila
Published on: August 20, 2019
13.6K
Congenital Sucrase-Isomaltase Deficiency: Same Mutation with Different Clinical Presentations
Fatma İssi İryancı1, Burcu Güven1, Murat Çakır1
1Department of Pediatric Gastroenterology, Karadeniz Technical University Faculty of Medicine, Trabzon, Turkey.
Summary
Congenital sucrase-isomaltase deficiency, typically autosomal recessive, can manifest symptoms in heterozygous individuals. This study explored genotype-phenotype links, revealing symptomatic cases with heterozygous mutations.
Area of Science:
- Genetics
- Gastroenterology
- Biochemistry
Background:
- Congenital sucrase-isomaltase deficiency (CSID) is an inherited disaccharidase disorder causing chronic diarrhea.
- Autosomal recessive inheritance is typical, but genotype-phenotype relationships require further elucidation.
Purpose of the Study:
- Investigate genotype-phenotype correlations in CSID within a family.
- Assess clinical manifestations in individuals with and without CSID-related gene mutations.
Main Methods:
- Pedigree analysis of an index case with a homozygous sucrase-isomaltase gene mutation (c.317G>A, p.C106Y).
- Comparison of clinical symptoms between family members with and without heterozygous or homozygous mutations.
- Evaluation of sacrosidase enzyme replacement therapy in symptomatic patients.
Main Results:
- A sucrase-isomaltase gene mutation (c.317G>A, p.C106Y) was identified in 27 heterozygous family members (24.7%).
- Symptomatic heterozygous individuals reported abdominal pain, gas irritability, bloating, and foul-smelling stools.
- Significant differences in gastrointestinal symptoms and food allergies were observed between mutated and non-mutated groups.
- Sacrosidase enzyme therapy showed clinical efficacy in improving symptoms.
Conclusions:
- CSID can present symptomatically in heterozygous individuals, challenging the typical autosomal recessive model.
- Further research is needed to fully understand CSID genotype-phenotype relationships and optimize management strategies.
Related Concept Videos
01:27Glucose Transporters
22.6K
Glucose transporters facilitate the transport of glucose across the cell membrane. In addition to glucose, some glucose transporters can also aid the movement of other hexoses such as fructose, mannose, and galactose.
Facilitated diffusion-glucose transporters (GLUTs) are encoded by the solute-linked carrier (SLC) family 2, subfamily A gene family, or SLC2A. The 14 GLUT protein members are distributed into three classes:
Facilitated diffusion-glucose transporters (GLUTs) are encoded by the solute-linked carrier (SLC) family 2, subfamily A gene family, or SLC2A. The 14 GLUT protein members are distributed into three classes:
22.6K
01:20Inborn Errors of Metabolism
148
Phenylketonuria (PKU) is a protein metabolism disorder characterized by high blood levels of the amino acid phenylalanine. This results from a mutation in the gene responsible for phenylalanine hydroxylase, an enzyme that converts phenylalanine into tyrosine. When this enzyme is deficient, phenylalanine builds up in the blood, leading to symptoms such as vomiting, rashes, seizures, growth deficiency, and severe mental retardation. An early diagnosis and a diet restricting phenylalanine intake...
148
01:22Lysosomal Hydrolases
3.8K
Lysosomes are the site for the degradation of macromolecules and biological polymers released during membrane trafficking events such as secretory, endocytic, autophagic, and phagocytic pathways. The membrane-enclosed area of the lysosome, called the lumen, contains hydrolytic enzymes active in an acidic environment. These acid hydrolases are functional at a pH between 4.5 and 5 and are involved in cellular processes such as cell signaling, energy metabolism, restoration of the plasma membrane,...
3.8K
01:21Overview of Protein Metabolism
913
Proteins are broken down into amino acids during digestion. Unlike fats and carbohydrates, which are stored for later use, proteins are not. Instead, amino acids are either used to produce ATP through oxidation or contribute to the creation of new proteins for the growth and repair of the body. Any surplus amino acids from the diet are converted into glucose or triglycerides rather than excreted.
Amino acids play various roles in the body once they are absorbed into cells. They are restructured...
Amino acids play various roles in the body once they are absorbed into cells. They are restructured...
913
01:43Incomplete Dominance
22.2K
Gregor Mendel's work (1822 - 1884) was primarily focused on pea plants. Through his initial experiments, he determined that every gene in a diploid cell has two variants called alleles inherited from each parent. He suggested that amongst these two alleles, one allele is dominant in character and the other recessive. The combination of alleles determines the phenotype of a gene in an organism.
22.2K
01:23Cystic Fibrosis: Pathogenesis
201
Cystic fibrosis (CF), an autosomal recessive disorder, significantly affects the function of exocrine glands. This genetically inherited disease is characterized by the production of thick and sticky mucus, which can severely affect various organs and systems in the body.
CF is primarily caused by a genetic mutation in a chromosome 7 gene coding for the cystic fibrosis transmembrane conductance regulator (CFTR) protein. The most common gene mutation leading to CF is the ΔF508 mutation,...
CF is primarily caused by a genetic mutation in a chromosome 7 gene coding for the cystic fibrosis transmembrane conductance regulator (CFTR) protein. The most common gene mutation leading to CF is the ΔF508 mutation,...
201