<h3 id="grouplabel1">Chosen gender: @( ChosenGender == 0 ? "no selection yet" : ChosenGender.ToString() )</h3>
<TelerikRadioGroup Data="@GenderOptions"
                   @bind-Value="@ChosenGender"
                   ValueField="@nameof(GenderModel.GenderId)"
                   TextField="@nameof(GenderModel.GenderText)" AriaLabelledBy="grouplabel1">
</TelerikRadioGroup>

@code {
    TelerikRadioGroup<GenderModel, int?> RadioGroupRef { get; set; }

    int ChosenGender { get; set; }

    List<GenderModel> GenderOptions { get; set; } = new List<GenderModel>
    {
        new GenderModel { GenderId = 1, GenderText = "Female" },
        new GenderModel { GenderId = 2, GenderText = "Male" },
        new GenderModel { GenderId = 3, GenderText = "Other" },
        new GenderModel { GenderId = 4, GenderText = "Prefer not to say" },
    };

    public class GenderModel
    {
        public int GenderId { get; set; }
        public string GenderText { get; set; }
    }
}

<div role="radiogroup" aria-labelledby="group_label_1">
    <h3 id="group_label_1" >Chosen gender: @( ChosenGender == 0 ? "no selection yet" : ChosenGender.ToString() )</h3>
<br />

<TelerikRadioGroup Data="@GenderOptions"
                   @bind-Value="@ChosenGender"
                   ValueField="@nameof(GenderModel.GenderId)"
                   TextField="@nameof(GenderModel.GenderText)">
</TelerikRadioGroup>
</div>

@code{
    TelerikRadioGroup<GenderModel, int?> RadioGroupRef { get; set; }

    int ChosenGender { get; set; }

    List<GenderModel> GenderOptions { get; set; } = new List<GenderModel>
    {
        new GenderModel { GenderId = 1, GenderText = "Female" },
        new GenderModel { GenderId = 2, GenderText = "Male" },
        new GenderModel { GenderId = 3, GenderText = "Other" },
        new GenderModel { GenderId = 4, GenderText = "Prefer not to say" },
    };

    public class GenderModel
    {
        public int GenderId { get; set; }
        public string GenderText { get; set; }
    }
}