... half of collagen triple helices will incorporate this abnormal protein and produce an abnormal collagen trimer, leading to ... HbS can be diagnosed by digestion with restriction enzyme MstII yielding only one 1.35kb fragment or by hemoglobin ... OI Type II: Caused by mutation in COL1A2 gene leading to production of protein with an abnormal (novel) structure; ... Thalassemia Intermedia: mild-moderate anemia caused by inheritance of 2 abnormal b-globin genes ...