SLC4A1 and histiocytic sarcoma: The diagnosis of HS in case 19 was done based on presence of mild hemolysis, presence of 9% spherocytes, LoRRca Osmoscan profile typical of HS and evidence of 21% decrease in spectrin content (interestingly, the patient showed a missense variant p. R870Q in SLC4A1 gene, see later).