Expanding the phenotypic and genetic spectrum of TUBB8 in female
infertility: Suggestions for genetic counseling
Abstract
Tubulin beta 8 class VII (TUBB8), a primate oocyte/embryo-specific
β-tubulin isotype, is a preferentially analyzed gene in the genetic
diagnosis of infertile women. Studies have currently identified 47
variants of this gene. However, the evaluation of its pathogenicity and
the resulting phenotypes vary, and this gene requires further study in
order to be included in genetic counseling analyses. We have performed a
whole exome sequencing (WES) screening of 385 infertile female subjects
and 400 controls, identifying 29 TUBB8 variants (of which 23 were
novel). These variants may be responsible for female infertility,
especially in the case of embryonic arrest, and their identification
further expands the variant spectrum of TUBB8. Our findings are the
first to report a new phenotype of large polar body in TUBB8 variant
patients and determine some recurrent variants that were specific for
complete cleavage failure. We have also illustrated some phenotypes of
TUBB8 variant patients and recommended using computational modeling
approach to assess the pathogenicity of novel TUBB8 variants,
particularly for maternally inherited variants. Our studies will
contribute in laying the foundation for the genetic counseling of
infertile women in the future.