▁in ▁new born s ▁and ▁progress ▁ag gress ively ▁within ▁the ▁first ▁few ▁months ▁of ▁life , ▁thus , ▁testing ▁for ▁ABC A 3 ▁and ▁SP - B ▁dis orders ▁should ▁pre clude ▁those ▁for ▁SP - C , ▁especially ▁when ▁inf ants ▁are ▁showing ▁sympt oms ▁of ▁I LD ▁or ▁diff use ▁lung ▁disease . ▁Dist in ctions ▁between ▁SP - B ▁and ▁ABC A 3 ▁are ▁ABC A 3 ▁tends ▁to ▁occur ▁in ▁families ▁with ▁ne on atal ▁lung ▁disease ▁history , ▁and ▁SP - B ▁testing ▁almost ▁un ne eded ▁in ▁older ▁children . ▁Late ▁on - set ▁conditions ▁with ▁inheritance ▁in ▁dominant ▁fashion ▁should ▁infer ▁SP - C ▁d ys function . ▁Ant ib od ies ▁against ▁pro SP - B , ▁pro SP - C , ▁SP - B , ▁SP - C , ▁and ▁ABC A 3 ▁have ▁been ▁thoroughly ▁developed , ▁which ▁makes ▁detection ▁for ▁these ▁prote ins ▁highly ▁accessible ▁and ▁accurate . ▁Im m uno ▁st aining ▁of ▁each ▁of ▁these ▁type ▁of ▁sur fact ant ▁d ys function ▁diff ers ▁in ▁absence ▁and ▁presence ▁of ▁specific ▁prote ins ▁and ▁pro pe pt ides , ▁thus ▁imm un oh ist och em ist y ▁can ▁help ▁de ci pher ▁which ▁type ▁of ▁def ic iency ▁is ▁being ▁de alt ▁with . ▁In ▁addition , ▁hypoth y roid ism ▁can ▁cause ▁dam aged ▁production ▁of ▁NK X 2 . 1 ▁prote ins , ▁which ▁can ▁lead ▁to ▁ins u fficient ▁trans cription ▁of ▁multiple ▁sur fact