Object Initialiser Comma Query
===

Having noticed a small mistake in my C# code (end of line 4):

    Domain.Models.Patient patient = new Domain.Models.Patient
    {
       PatientId = patientId,
       StudyID = studyId,
    };

I don't get any build error, or runtime errors - when there is an errant comma at the end of studyId.

Why is this, and does it really matter?