[PAGID] cvid and 4q deletion

[Ashish Kumar]

Dear Friends,

I recently saw an 8 year old boy for a second opinion for chronic ITP and new onset autoimmune hemolytic anemia and hypogammaglobulinemia. I also noted that he had a single palmar crease in one hand, a pre-auricular tag and the family then informed me that he was diagnosed with a horseshoe kidney. I checked a karyotype and sure enough he has a micro-deletion on the long arm of chromosome 4. With a high resolution SNP array, our genetics lab narrowed down the mission region to 10.4 mb. The missing piece maps to within the boundaries of the region described by Bodo Grimbacher in familial cases of cvid [Eur J Hum Genet. 2006 Jul;14(7):867-75]. So, I suspect there are genes within this region that might be operative in this disease, with a large deletion in the patient I describe and smaller changes/point mutations in other cases. But this region is still 10.4 mb long, with 75 known genes. I am looking for other cases that might have had 4q changes that will help us narrow down the region. The coordinates are 4q22.3q24(96,800,854-107,166,936). It would be better if we had some idea what to go after rather than just sequence the whole region.

Thanks!
Ashish Kumar

Ashish Kumar, MD, PhD
Assistant Professor
Cincinnati Children's Hospital Medical Center
Cincinnati, OH