Definition:

Primordial dwarfism-immunodeficiency-lipodystrophy syndrome (PDIL) is a novel microcephalic primordial dwarfism disorder caused by mutations in PRIM1 encoding the catalytic subunit of DNA primase. PRIM1 protein levels were markedly reduced in patient cells. PRIM1 deficiency results in growth restriction, microtia and lymphopenia, similar to other replication-associated disorders. However, there are distinctive clinical features for individuals with PRIM1 deficiency, particularly early childhood mortality. This might be accounted for by the significant B-cell lymphopenia and accompanying hypogammaglobulinemia.