Editing COPII (section)

==Role in disease==
Lethal or pathogenic variants of most COPII proteins have been described. Loss of Sar1B in mice results in death soon after birth.<ref name=Lu2020>{{cite journal |vauthors=Lu CL, Kim J |title=Consequences of mutations in the genes of the ER export machinery COPII in vertebrates |journal=Cell Stress Chaperones |volume=25 |issue=2 |pages=199–209 |date=March 2020 |pmid=31970693 |pmc=7058761 |doi=10.1007/s12192-019-01062-3 |url=}}</ref> In humans, inheriting two copies of certain SAR1B variants results in [[Chylomicron retention disease]],<ref name=Peotter2019/> and loss of Sar1B causes a combination of chylomicron retention disease and the neuromuscular disorder [[Marinesco–Sjögren syndrome]].<ref name=Lu2020/>

Loss of Sec23A is lethal to mice ''in utero''.<ref name=Lu2020/> In humans, a Sec23A variant causes [[Cranio-lenticulo-sutural dysplasia]], while Sec23B variants are associated with the bone marrow disease [[congenital dyserythropoietic anemia type II]] and some [[cancer]]s.<ref name=Lu2020/><ref name=Peotter2019/> Mice without Sec23B die soon after birth.<ref name=Lu2020/> [[Halperin-Birk syndrome]] (HLBKS), a rare autosomal recessive neurodevelopmental disorder, is caused by a null mutation in the SEC31A.<ref>{{Cite journal |last1=Halperin |first1=Daniel |last2=Kadir |first2=Rotem |last3=Perez |first3=Yonatan |last4=Drabkin |first4=Max |last5=Yogev |first5=Yuval |last6=Wormser |first6=Ohad |last7=Berman |first7=Erez M |last8=Eremenko |first8=Ekaterina |last9=Rotblat |first9=Barak |last10=Shorer |first10=Zamir |last11=Gradstein |first11=Libe |last12=Shelef |first12=Ilan |last13=Birk |first13=Ruth |last14=Abdu |first14=Uri |last15=Flusser |first15=Hagit |date=2018-11-21 |title=''SEC31A'' mutation affects ER homeostasis, causing a neurological syndrome |url=http://dx.doi.org/10.1136/jmedgenet-2018-105503 |journal=Journal of Medical Genetics |volume=56 |issue=3 |pages=139–148 |doi=10.1136/jmedgenet-2018-105503 |pmid=30464055 |s2cid=53717389 |issn=0022-2593|url-access=subscription }}</ref>