Abstract
AIMS: In this study we analyzed the degree of genetic homozygosity among spina bifida patients with different degrees of neurogenic lesion (N = 82), as well as their clinical and neurological characteristics, compared to healthy control individuals (N = 100). METHODS: According to clinical and electromyographic findings, we separately assessed the type of neurogenic lesion (paresis or paralysis). Regarding the degree of neurogenic lesion, patients were classified into three groups: mild, moderate and severe. We analyzed six muscles. For assessing the degree of individual genetic homozygosity, we tested the presence and distribution of 15 homozygous recessive characteristics (HRC). RESULTS: The predominant type of neurogenic lesion was paresis. Every third evaluated muscle was affected in the group with mild neurogenic lesion, while more than half were affected in the group with severe neurogenic lesion. The average values of HRCs among different groups of patients and the control showed the population-genetic differences that exist among them (control (HRC/15)=3.0±0.2; mild (HRC/15)=3.6±0.2; moderate (HRC/15)=4.8±0.3; severe neurogenic lesion (HRC/15)=5.0±0.3). CONCLUSIONS: Spina bifida patients have a significant increase of recessive homozygosity and a decreased variability compared to the control group. As neurogenic lesions are more severe, more affected muscles are present, as well as the increase of individual recessive homozygosity.