Moreover, the ratio of threonine and serine to isoleucine, leucine and valine in the amniotic fluid of spina bifida fetus is higher than normal.

• 但脊柱裂羊水中的苏氨酸、丝氨酸与异亮氨酸、亮氨酸、缬氨酸的比值明显地高于正常值。