Majeed syndrome is an exceedingly rare disorder that was first described in 1989. There have been 13 total cases documented in 4 Middle Eastern families and 1 Indian family. It is an autosomal recessive disorder caused by mutations in the LPIN2 gene on chromosome 18. The gene encodes the lipin-2 protein, a phosphatidic acid phosphatase important in triglyceride synthesis and dephosphorylation of phosphatidic acid. Lipin-2 also plays a significant role in inflammation by negatively regulating the NLRP3 inflammasome.

Affected individuals present with the triad of microcytic chronic dyserythropoietic anemia (CDA), chronic recurrent multifocal osteomyelitis (CRMO), and an inflammatory dermatosis.

CDA presents in the first year of life and ranges in severity from mild to transfusion dependent.

Initial presentation of CRMO is usually between 3 weeks to 2 years of age but onset up to 8 years of age has been reported. Its course is characterized by 1-3 exacerbations a month, lasting a few days each, and likely affecting the patient for life. Exacerbations comprise fever, severe joint pain, and soft tissue swelling, predominantly around large joints. Prolonged disease often leads to delayed bone age, growth retardation, and permanent flexion contractures.

The inflammatory dermatosis is not a consistent feature. The most common skin manifestation is Sweet syndrome, which presents before 3 years of age. One patient with Majeed syndrome developed cutaneous pustulosis.