22 June 2026
: Case report 
Suspected Adult-Onset Congenital Myasthenic Syndrome Associated With a Heterozygous CHRND Variant in a Patient With Seropositive Rheumatoid Arthritis: A Case Report
Challenging differential diagnosis, Congenital defects / diseases
Khaled Abdulwahab Amer
AE 1*, Hanan Hassan Almalki AF 2, Faisal Saud Alhudaithi BD 3
DOI: 10.12659/AJCR.952887
Am J Case Rep 2026; 27:e952887
Table 4 Genetic testing results.
| Test | Gene | Variant | Inheritance | Clinical significance |
|---|---|---|---|---|
| WES (2023) | Heterozygous likely pathogenic | AR | Suggestive but inconclusive | |
| WGS (2025) | Heterozygous pathogenic | AD | HLRCC cancer risk | |
| WGS (2025) | Heterozygous pathogenic | AR | Consistent with/suggestive of CMS; single heterozygous variant, not confirmatory (CMS classically AR) | |
| WGS (2025) | Hemizygous VUS | X-linked | Uncertain significance | |
| WGS (2025) | Heterozygous pathogenic | AR | Carrier for GSD Ia | |
| WGS (2025) | Heterozygous likely pathogenic | AR | Carrier for immunodeficiency 67 | |
| Abbreviations: AD, autosomal dominant; AR, autosomal recessive; CMS, congenital myasthenic syndrome; GSD, glycogen storage disease; HLRCC, hereditary leiomyomatosis and renal cell cancer; VUS, variant of uncertain significance; WES, whole-exome sequencing; WGS, whole-genome sequencing. | ||||