GeneDx :: Tests :: Shwachman-Diamond Syndrome

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Shwachman-Diamond Syndrome

SBDS

Using genomic DNA obtained from buccal (cheek) swabs or blood (5cc in EDTA --Blood can only be used if the patient has not previously had a bone marrow transplant), the intron/exon boundries and exons 1 through 5 of the SDBS gene on chromosome 7q11 are screened by bi-directional sequence analysis. There is an unprocessed pseudogene copy of SBDS located 5.8 Mb distally which is 97% identical to SBDS but contains deletions and nucleotide changes that disrupt the coding potential. Gene conversion mutations involving the pseudogene account for approximately 75% of the alleles associated with SBDS, with 89% of affected individuals carrying one converted allele and 60% carrying two alleles. The majority of the conversion events involve exon 2, with several recurrent mutations identified. Thus, primers have been designed to amplify the region of the gene encompassing the true exon 2-3 region, as opposed to the homologous portion of the pseudogene. Then primers specific to each of exon 2 and 3 are used to re-amplify fragments from the primary product. Primers for the remainder of the gene were also designed to specifically amplify only the transcribed gene. Prenatal diagnosis is available once the mutation in a family has been defined.

Information Sheet, including prices and CPT codes
Consent Document
Genetic Test Sample Submission Form (Test Requisition Form) including Payment Options

Shwachman-Bodian, Shwachman Diamond, Shwachman-Diamond, Pancreatic insufficiency, exocrine, steatorrhea, malabsorption, anemia, nephrocalcinosis, bone marrow failure, bone marrow, Congenital Lipomatosis of Pancreas , pancreatic lipomatosis, leukemia, short stature, SBDS, SDS, failure to thrive