Ancestral sin (Greek: προπατορική αμαρτία or προπατορικό αμάρτημα, more rarely προγονική αμαρτία) is the object of a Christian doctrine taught by the Eastern Orthodox Church. Some identify it as "inclination towards sin, a heritage from the sin of our progenitors". But most distinguish it from this tendency that remains even in baptized persons, since ancestral sin "is removed through baptism".
The Greek theologian John Karmiris writes that "the sin of the first man, together with all of its consequences and penalties, is transferred by means of natural heredity to the entire human race. Since every human being is a descendant of the first man, 'no one of us is free from the spot of sin, even if he should manage to live a completely sinless day.' ... Original Sin not only constitutes 'an accident' of the soul; but its results, together with its penalties, are transplanted by natural heredity to the generations to come ... And thus, from the one historical event of the first sin of the first-born man, came the present situation of sin being imparted, together with all of the consequences thereof, to all natural descendants of Adam."
Roman Catholic Church 
The Catechism of the Catholic Church, the Greek translation of which uses "προπατορική αμαρτία" (literally, "ancestral sin") where the Latin text has "peccatum originale", states: "Original sin is called 'sin' only in an analogical sense: it is a sin 'contracted' and not 'committed' - a state and not an act. Although it is proper to each individual, original sin does not have the character of a personal fault in any of Adam's descendants". And Eastern Orthodox teaching likewise says: "It can be said that while we have not inherited the guilt of Adam's personal sin, because his sin is also of a generic nature, and because the entire human race is possessed of an essential, ontological unity, we participate in it by virtue of our participation in the human race. 'The imparting of Original Sin by means of natural heredity should be understood in terms of the unity of the entire human nature, and of the homoousiotitos of all men, who, connected by nature, constitute one mystic whole. Inasmuch as human nature is indeed unique and unbreakable, the imparting of sin from the first-born to the entire human race descended from him is rendered explicable: "Explicitly, as from the root, the sickness proceeded to the rest of the tree, Adam being the root who had suffered corruption" (St. Cyril of Alexandria)'".
See also 
- The Nature of Sin; same text also at The Nature of Sin
- St Nikodemos the Hagiorite: Exomologetarion; cf. "Το βάπτισμα ... αποβάλλει την παλαιά φύση της αμαρτίας (το προπατορικό αμάρτημα)" (Ανδρέα Θεοδώρου: Απαντήσεις σε ερωτήματα δογματικά (εκδ. Αποστολικής Διακονίας, 1997), p. 156-161).
- A Discussion of the Orthodox Perception of the Nature of God
- Archpriest Alexander Golubov: Rags of Mortality: Original Sin and Human Nature
- Catechism of the Catholic Church, 404-405
- Correct word would be homoousiotes;the quoted text errouneously uses its genitive form homoousiotetos (with 'i' instead of 'e' in the paenultimate syllable following a mixed Greek transliteration scheme with both modern and classical elements)
- Archpriest Alexander Golubov: Rags of Mortality: Original Sin and Human Nature quoting John Karmiris, A Synopsis of the Dogmatic Theology of the Orthodox Catholic Church, trans. from the Greek by the Reverend George Dimopoulos (Scranton, Pa.: Christian Orthodox Edition, 1973), p. 36