Related Experiment Video
Updated: Jun 18, 2026

Immunoglobulin Gene Sequence Analysis In Chronic Lymphocytic Leukemia: From Patient Material To Sequence Interpretation
Published on: November 26, 2018
Clinical characteristics and genotype-phenotype correlation in 62 patients with X-linked agammaglobulinemia
Pamela P W Lee1, Tong-Xin Chen, Li-Ping Jiang
1Department of Paediatrics and Adolescent Medicine, The University of Hong Kong, Hong Kong, China.
Introduction:
X-linked agammagobulinemia (XLA) is a primary immunodeficiency disorder caused by Bruton's tyrosine kinase (Btk) gene mutation. Recent studies suggested genotype-phenotype correlation in XLA, but a definitive association remains controversial.
Patients And Methods:
We examined the relationship between specific Btk gene mutations and severity of clinical presentation in 62 patients with XLA. Disease severity was assessed by the age of disease onset and the presence of severe infections, while mutations were classified into severe and mild based on structural and functional consequence by bioinformatics analysis.
Results:
Fifty-six Btk mutations were identified in 62 patients from 57 kindreds. Variation in phenotypes was observed, and there was a tendency of association between genotype and age of disease onset as well as occurrence of severe infections.
Conclusion:
A critical analysis of the circumstances upon presentation also revealed that under-recognition of recurrent infections and relevant family history are important hurdles to timely diagnosis of XLA.
Related Concept Videos
Sex-linked Disorders
Pedigree Analysis
X-linked Traits
X-linked Traits
Myasthenia Gravis ll: Pathophysiology
Lethal Alleles
Lucien Cuénot discovered lethal alleles in 1905 while studying the inheritance of coat color in mice. The agouti gene is responsible for the color of the coat in mice. This gene codes for an agouti-signaling protein, which is responsible for melanin distribution in mammals. The wild-type allele gives rise to gray-brown coat color in mice, while the mutant allele gives rise to yellow coat color. In addition to coat color, the agouti gene is associated with the yellow...
