随体区指近端着丝粒染色体(AC)短臂末端一个球形染色体节段(随体)与其毗邻的核仁形成区(NOR)共同构成。该区在人群中表现比较恒定的微小形态变异,并按盂德尔方式遗传,此类变异称随体区变异型(Satellite variant,SV)。 SV在人群中发生频率较高,通常不引起临床症状,并在家族内恒定遗传,因而有学者认为它是一种多态现象,但不排除受某些环境或遗传因素影响时,SV可能引起发育异常。是否可视SV为染色体正常结构变 The satellite zone is defined by a globular chromosome segment (satellite) near the short arm of the proximal centromeric chromosome (AC) with its adjacent nucleolar organizer region (NOR). This region shows a relatively small morphological variation in the human population and is inherited by the Mendelian method. Such variants are referred to as Satellite variant (SV). SV occurs frequently in the crowd, usually does not cause clinical symptoms, and in the family constant genetic, so some scholars think it is a polymorphism, but does not rule out the influence of certain environmental or genetic factors, SV may cause Abnormal development. Visual SV is the normal structure of chromosome changes