TRIM21 and respiratory failure: Severe hypokalemia, a potential complication, can result in hypokalemic muscle paralysis characterized by generalized muscle weakness and, in severe cases, respiratory muscle involvement [18,19]. In the presented case, the initial presentation of the patient was hypokalemia, causing generalized muscle weakness; as the muscular involvement progressed, it eventually led to respiratory failure. Given the urgency of identifying the cause of this electrolyte disturbance, laboratory results revealing positive ANA, anti-Ro/SSA, and RF findings raised a strong suspicion of SS.