Manaless

A person is deemed manaless when they are shown to have a complete lack of affinity for magic.
The key difference between someone less than talented with magic and one who is manaless is that the latter's lack of magic is near absolute. Even if an average person can't conjure a single spell, there is usually still a passive flow of mana that they generate. In a manaless, that flow simply does not exist, leaving them completely cut off from magic entirely.

Transmission & Vectors

The trait of manaless is seemingly acquired at birth and is believed to be possible to be passed down to subsequent generations.
Scholars researching the trait consider it a recessive gene as families having both parents be confirmed magic users have been recorded as yielding manaless children.

Causes

The exact root cause of the condition is unknown nor is the noticable uptick in number of manaless in recent years.
The most prevailent theory is that it is a recessive trait that is for some reason incompatible with the use of mana to the point of the body rejecting magic altogether.

Symptoms

There has been no officially recognized health ramifications for those who are manaless. 
The single main symptom of the condition is the afflicted's complete inability to use magic.

Treatment

There is no known method for reversing or undoing a manaless person's lack of magical affinity.

Prevention

As being manaless is an in-born condition, families with considerable magic affinity such as noble houses often track and consult the family trees of potential spouses. Specifically, they look for family history of manaless children versus children with high magical affinity.

Cultural Reception

In societies where great import is placed on magical ability, being manaless or even having a close family member be known as manaless can be significant black mark for a person.
It is not unheard of for noble families to disown manaless children as the condition severely hampers their marriage prospects for other houses. Even if the child is allowed to remain in the family, rarely will they be considered eligable to be a potential heir for the title of head of house.
In Elven culture, the condition is treated as more problematic as magic is seen as blessing from the gods to be used to better understand nature and their environment. A manaless Elf and their family could face ostracization, their condition potentially being seen as a curse or punishment for some past act.

Type

Magical

Origin

Natural

Cycle

Chronic, Congenital

Rarity

Uncommon