How is Anderson’s Disease Diagnosed?
Below Mentioned Are The Ways To Diagnose Anderson’s Disease:
The diagnosis of Anderson’s disease or chylomicron retention disease is frequently delayed because of their nonspecific signs and symptoms. Genetic testing is most widely used to identify the change in the chromosome, gene, or protein that is associated with chylomicron retention disease. The consequences of a genetic test can confirm the suspected genetic condition or help to determine a person’s chance of developing or passing on a genetic disorder.
Recently, the SAR1B gene was identified as responsible for Anderson’s disease or chylomicron retention disease. Genomic DNA isolation from whole blood of affected person and sequencing of all the exons of the SAR1B genes, including the intron-exon boundaries can reveal the SAR1B mutation. Genotyping makes it possible to identify mutated gene SAR1A/SAR1B which causing Anderson’s disease or chylomicron retention disease.
Duodenal biopsies may help in determining the expression of SAR1A proteins. The total amount of SAR1 proteins in the intestine predicts Anderson’s disease or chylomicron retention disease in patients as compared to normal individuals. Intestinal biopsies done for a immunohistochemical analysis will identify the presence of SAR1A protein.
Through duodenal biopsies a localization of Sar1 proteins can be done with immunostains through nova red with use of chicken polyclonal antibody and anti-chicken against the recombinant SAR1A protein found in humans.
Parental lipid screening could possibly clarify the diagnosis. Lipid profile evaluation such as total cholesterol and triglyceride concentrations; RBC analysis (acanthocytosis-theory appearance of cells), liver enzyme analysis (ALT, AST, & bilirubin), liposoluble vitamins ratios, and plasma fatty acids levels are some of the routine biochemical assays support the diagnosis of Anderson’s disease or chylomicron retention disease. The unspecific decrease of vitamin E and K denotes the most severe form of this condition. Vitamin K deficiency can be further confirmed by coagulation test.
Anthropometry is described as the scientific study of the measurements and proportions of the human body. In case of chylomicron retention disease, the affected person shows failure to thrive in early infancy (within 10 months) or childhood (less than 3 years). Some symptoms may help in diagnosis and include diarrhea due to chronic malabsorption during initial infancy, bouts of frequent vomiting and a distended abdomen early in the infancy. Neurological complication like areflexia, decreased proprioception, and ataxia is something that is very rare in childhood. Consanguineous marriage (blood relation) is frequent in patients with the disorder. An absence of hypocholesterolemia in both parents favors CRD.
Endoscopy can reveal the abnormal duodenum content i.e. white deposition of lipid droplets in the villi. It may due to enterocytes which are unacceptably distended by the lipid deposition. Electron microscopy analysis can reveal the aggregation of chylomicrons in the duodenum biopsy.
The diagnosis is sometimes delayed (may take months) because the symptoms are non-specific. A confirmative diagnosis of this condition is made based on the history of laboratory tests showing an abnormal lipid profile, evidence of fat malabsorption, and symptoms of chronic diarrhea. An upper endoscopy along with a detailed histology will reveal a deficiency of vitamin E along with presence of fat-laden enterocytes. There is also elevation of creatine kinase and there is a common finding of hepatic steatosis. A genetic test will reveal mutation of the Sar1b gene.