The concept of Original Sin is a late Christian notion (2nd Century). It has no foundation in the Hebrew Scriptures (Tanakh).
If Gnosticism would have won we wouldn’t be having this discussion.

If you want scriptural support I’d look in the Greek Scriptures
I have to disagree with you, original sin has foundation in the Hebrew Scriptures.
See God's response to the first sin below...He pronounces curses upon Adam and Eve, thus He identifies their sin and also responds to it.
13 Then the Lord God said to the
woman, “What is this you have done?”
The woman said, “The serpent
deceived me, and I ate.” [the sin]
14 So the Lord God said to the serpent, “Because you have done this,
“Cursed are you above all livestock
and all wild animals!
You will crawl on your belly
and you will eat dust
all the days of your life.
15 And I will put enmity
between you and the woman,
and between your offspring and hers;
he will crush your head,
and you will strike his heel.”
16
To the woman he said,
“I will make your pains in childbearing very severe;
with painful labor you will give birth to children.
Your desire will be for your husband,
and he will rule over you.”
17
To Adam he said, “Because you listened to your wife and ate fruit from the tree about which I commanded you, ‘You must not eat from it,’
“Cursed is the ground because of you;
through painful toil you will eat food from it
all the days of your life.
18 It will produce thorns and thistles for you,
and you will eat the plants of the field.
19 By the sweat of your brow
you will eat your food
until you return to the ground,
since from it you were taken;
for dust you are
and to dust you will return.”
20
Adam named his wife Eve, because she would become the mother of all the living.
21 The Lord God made garments of skin for Adam and his wife and clothed them. 22 And the Lord God said, “The man has now become like one of us, knowing good and evil. He must not be allowed to reach out his hand and take also from the tree of life and eat, and live forever.” 23 So the Lord God banished him from the Garden of Eden to work the ground from which he had been taken. 24 After he drove the man out, he placed on the east side of the Garden of Eden cherubim and a flaming sword flashing back and forth to guard the way to the tree of life.
Also.....
Exodus 20:4-6:
You shall not make for yourself an image in the form of anything in heaven above or on the earth beneath or in the waters below. 5 You shall not bow down to them or worship them; for I, the Lord your God, am a jealous God,
punishing the children
for the sin of the parents to the third and fourth generation of those who hate me, 6 but showing love to a thousand generations of those who love me and keep my commandments.
and...
Jeremiah 31:29-34:
29 “In those days people will no longer say,
‘The parents have eaten sour grapes,
and the children’s teeth are set on edge.’
30 Instead, everyone will die for their own sin; whoever eats sour grapes—their own teeth will be set on edge.
31 “The days are coming,” declares the Lord,
“when I will make a new covenant
with the people of Israel
and with the people of Judah.
32 It will not be like the covenant
I made with their ancestors
when I took them by the hand
to lead them out of Egypt,
because they broke my covenant,
though I was a husband to
declares the Lord.
33 “This is the covenant I will make with the people of Israel
after that time,” declares the Lord.
“I will put my law in their minds
and write it on their hearts.
I will be their God,
and they will be my people.
34 No longer will they teach their neighbor,
or say to one another, ‘Know the Lord,’
because they will all know me,
from the least of them to the greatest,”
declares the Lord.
“For I will forgive their wickedness
and will remember their sins no more.”
So original sin did exist or was viewed as such in O.T. just as Romans declares. Exodus and Jeremiah above remind us of this. Jeremiah goes further and describes that there will be a future change of the LAW...referring to the changes to accompany the birth and reign of the Messiah.