Candidate Gene Sequencing for Choanal Atresia

Principal investigator:

David Andrew Merriwether
Binghamton University
September 1, 2021 – August 31, 2024
$11,999

Choanal atresia (CA) is the most common serious genetic defect in camelids and is common in alpacas. The inability to breathe through the nose while nursing usually leads cria to develop aspiration pneumonia and most die or are put down within a week. Recent findings in mice have shown that disabling the gene Retinol Dehydrogenase 10 (RDH10) led to babies born with choanal atresia. RDH10 binds with another protein, DHRS3, to form the Retinoid Oxidoreductive Complex (ROC). We propose to sequence the entire genes for RDH10 and DHRS3, including non-coding flanking sequences, to search for polymorphisms associated with CA, wry-face or other facial abnormalities and/or Polydactyly. We include wry-face and polydactyly because they are very commonly found in animals with CA or in close relatives of animals with CA. I have called this dominant syndromic choanal atresia. We currently have 29 DNA samples from CA cria, and a larger number of unaffected relatives of those affected cria. We will collect more up until we begin sequencing. All the samples we can acquire with CA, wry-face, or polydactyly will be sequenced, along with an equal number of unaffected animals. The Merriwether Lab at Binghamton university has a camelid DNA Bank of over 1000 DNA samples from camelids and an additional 600 blood spots from Peru still to be extracted. We have an Illumina MiSeq next generation sequencer and we will be able to sequence all these samples for the approximately 60,000+ base pairs of both genes (introns included).