Welcome to the Leukocyte Adhesion Deficiency Web Site

Patient Genetic Information - L.A.D. Type 1 Variant:

According to Prof. Dirk Roos, Ph.D. Head (retired), Dept. of Experimental Immunohematology at Sanquin Research at CLB in the Netherlands, my genetic defects are described as follows:

"On one chromosome 21 ... you have a mutation that changes a guanosine into cytidine, at position 691 in exon 6 of the CD18 gene INTG2. This mutation causes a change from the amino acid Aspartate into the amino acid Histidine at position 231 in the beta-2 integrin protein (also called CD18). This is a special mutation, because it causes the expression of a non-functional protein (usually the mutations lead to absence of the protein).

We now found that you have another mutation on the other chromosome 21. This is a change from guanosine into adenosine, at position 755 in exon 7 of INTG2. This mutation changes the genetic information for the amino acid Tryptophane at position 252 in CD18 into the genetic information that codes for Stop of protein synthesis. Usually, such a change leads to instability of the messenger RNA that brings the genetic information from the gene to the protein synthesis site in the cells. That explains why this mutation was not previously found, because other researchers use the genetic information from the messenger RNA, whereas we use the information from the CD18 gene itself.

In scientific terms, you have the following mutations in INTG2. On one allele G691C, leading to D231H; on the other allele G755A, leading to W252X."

Prof. Roos, further describes the nature of the genetic defect(s), saying:

"...you are the only one with these mutations, as far as I know. A mutation that leads to a stop codon is not unusual, but at this particular position it is unique. Also the mutation that leads to expression of an nonfunctional CD18 protein is very rare...

Patient Information - L.A.D.I.A.S.:

For information on Leukocyte Adhesion Deficiency Induced Autoimmune Syndrome or L.A.D.I.A.S. please click here.