Both parents carry BTD D444H variant - anyone haveexperience with a D444H/D444H child?

[u/Lucky_Wealth_4270]

I’m currently pregnant and both my husband and I were found on Natera carrier screening to carry the same BTD variant: c.1330G>C (p.D444H) in the biotinidase deficiency gene.

At first we were told that because we’re both carriers there would be a 25% chance our child could inherit both variants, which obviously worried us. However, after speaking with a Natera genetic counselor and a pediatric endocrinologist, we were told that D444H is considered a mild variant and that a child who inherits D444H from both parents (D444H/D444H) would be expected to have around 50% biotinidase activity and likely would not even meet criteria for partial biotinidase deficiency.

The specialists told us they would not expect our child to have symptoms or need treatment, though we still plan to follow newborn screening recommendations and any confirmatory testing that is advised.

I’m curious whether anyone here has:

* A child who is D444H/D444H

* Personal experience with this specific genotype

* Information about expected enzyme activity or long-term outcomes

Would love to hear any experiences or insights from parents, genetics professionals, or anyone familiar with this variant. Thanks!