Investigation of severe combined immunodeficiency (SCID) disease of Arabian horses raised at the state stud farms in Turkey

Abstract

Summary:Severe Combined Immunodeficiency (SCID) is a lethal and autosomal recessive hereditary disorder, which has frequently been reported in Arabian horses, dogs, mice and humans. The genetic basis of equine SCID is 5-base pairs deletion in the DNA-dependent protein kinase catalytic subunit (DNA-PKcs) gene. Up to date, there is no information on the presence of SCID in Arabian horses reared in Turkey either by clinical observation or molecular diagnosis. The main aims of this study were to investigate the presence of SCID mutant allele carrier and to determine SCID incidence in Turkey using molecular techniques. In the study, DNA samples were obtained from 239 Arabian horses raised in state stud farms of Turkey (Karacabey, n=70; Anadolu, n=70 and Sultansuyu, n=99) and they were analyzed using DNA-PKcs gene specific polymerase chain reaction and fragment analysis by capillary electrophoresis. The result of the study showed that, none of the examined Arabian horses has SCID mutation on their responsible gene region. In conclusion, no SCID carrier was identified among examined stud Arabian horses that were representing the 65.5% (239 out of 365) of all officially registered stud animals in Turkey. It is believed that, this first genetic screening study focused on the SCID determination at national level and the evidence of the disease absence have the potential to increase breeding value of Arabian horses originated from Turkey.

Investigation of the SCID mutant allele in Turkish Arabian horses reared in some private farms of the Eskişehir region in Turkey

“…DNA sequencing was used to investigate the five-nucleotide deletion in the DNA-PKcs gene in Arabian horses reared on Eskişehir private farms. Cinar Kul et al [19] showed that there were no SCID genetic defects in Turkish Arabian horse populations in state breeding farms. Supporting the previous study, our research indicates that all samples obtained from the private horse farms of Eskisehir were normal in terms of SCID hereditary defects.…”

“…Several previous genetic studies have investigated the five nucleotide deletion in the DNA-PKcs gene using primers that yield a PCR product of 521 bp [25], 259 bp [15], 235 bp [16], 179 bp [10], 174 bp [22], 169 bp [8,26], 163 bp [1,9,19,27], 162 bp [11], and 135 bp [13,17] in different Arabian horse populations.…”

“…To detect wild and mutant SCID alleles, the amplified PCR products were electrophoresed on 10% [10], 8% [13,15], and 6% Polyacrylamide gel [8,27], 4% agarose gel [17], or capillary electrophoresis [9,11,16,19]. In addition to electrophoresis, sequencing analysis could be performed to identify the genotypes of a population in terms of the presence/absence of SCID mutant alleles, as in these studies [1,25].…”

“…Among Arabian horse populations tested using molecular methods, the SCID mutant gene was detected in the USA [8], the UK [9], Brazil [10], Morocco [11], Egypt [1], and South Africa [12], but could not be detected in Ukraine [13], Syria [14], Iran [15], Romania [16], Slovenia [17], Poland [18], or Turkey [19]. There was only one study on SCID in Turkish Arabian horses.…”

Türkiye Arap Atı Popülasyonunda LFS ve PSSM-I Hastalıklarının Moleküler Taraması

“…The samples were collected in a previous study [12] . Also positive control samples carrying the mutations were sent by Dr. Brooks and Dr. McCue, for LSF and PSSM-I diseases respectively.…”