22q11.2 deletion syndrome is associated with DiGeorge syndrome, velo-cardiofacial syndrome and Opitz G/BBB syndrome.
A patient with 10p13 deletion may show features that overlap with DiGeorge syndrome.
Clinical features:
(1) facial dysmorphism
(2) neurodevelopmental delay (mental-motor retardation)
Laboratory features:
(1) mean platelet volume >= 8.6 fL (presence of macrothrombocytes)
(2) platelet count <= 265,000 per µL
(3) MPV to platelet count ratio >= 3.3
MPV to platelet count ratio =
= (mean platelet volume) / ((platelet count per µL) / (10^5))
If multiple findings are present, then the patient should be tested for 22q11.2 deletion by FISH analysis.
If there are no macrothrombocytes (MPV normal), then test for the 10p13 deletion.