Severe combined immunodeficiency with reticular dysgenesis

This code describes a rare and severe form of primary immunodeficiency characterized by a complete absence of T-cells and B-cells, along with a deficiency in granulocytes and erythrocytes. It results from a defect in hematopoietic stem cell differentiation, leading to profound susceptibility to infections. Infants with this condition typically present with recurrent, life-threatening infections and failure to thrive.

Use this code for documented cases of severe combined immunodeficiency specifically identified as having reticular dysgenesis. This diagnosis is typically made in infancy based on clinical presentation, profound lymphopenia, and specific genetic testing confirming the underlying defect. Documentation should clearly state "reticular dysgenesis" in conjunction with SCID.

• Ensure documentation explicitly states "reticular dysgenesis" to differentiate from other SCID types.
• Do not use this code for other forms of SCID without documented reticular dysgenesis; refer to other D81 subcategories.
• Consider sequencing this code as the primary diagnosis when it is the reason for the encounter or hospitalization.