Biotinidase Deficiency is a rare metabolic disorder.

Biotinidase Deficiency

When my youngest daughter was only a week old I got a phone call that no parent ever wants to get. It said that she tested positive on the “heel stick” blood test, and we would need to be at Primary Children’s Hospital within the next 2 days for more testing. She went on to explain that the positive test was for Biotinidase Deficiency. She also explained a little about Biotinidase deficiency, which I had never heard of. This nurse told me that it was a genetic disorder and so my other children would need to be tested, as well as me and my husband, to see if we were carriers for the disorder.

As I was packing things and getting ready to travel to Salt Lake, I was doing laundry when I twisted just right, throwing my back out of whack and dropping to my knees. (So you see, doing laundry IS dangerous). Now we had to travel 300 miles with a newborn baby, a 2/12-year-old, and a 6-year-old, when I was in so much pain, I could barely move. I also had to drive part of the way because my husband refuses to drive in the city. Then there was the whole emotional thing about something being wrong with my baby and possibly other children.

To make a long story short, and after 3 trips to Salt Lake and a lot of blood draws and needle sticks, as well as urine tests. (Have you ever tried to get a urine sample from a 2 1/2-year old? Let me tell you it is not easy). All 3 of my children were diagnosed with Biotinidase Deficiency, and both my husband and I are carriers for the disorder. The good news about this is there is a simple treatment for it. My children each have to take a supplement of Biotin twice a day for the rest of their lives.

What is Biotinidase Deficiency?

My children are now 11, 13, and 17. My 17-year-old son needed to write an expository essay for his English class. I wanted him to write about something that is meaningful to his life. He should write about Biotinidase Deficiency. I also wanted him to write it for his sisters, so they can understand why they take medicine and why they need it. So he wrote an essay and a power point presentation, keeping in mind that his younger sisters were the audience he was writing it for. It was to help them understand. So with his permission, I am adding it here. Maybe someone who reads this will need to have a simplified version of what this disorder is. Many things that we read are written as medical journals, and difficult for “regular” people to understand.



March 4, 2019

            Why do we take Biotin? 

We take it because we have a disorder called Biotinidase Deficiency.  Biotinidase Deficiency is a metabolic disorder where the enzyme that processes the vitamin, Biotin, is missing and without that enzyme our bodies could have problems.

  What causes Biotinidase deficiency?

Biotinidase Deficiency is a hereditary disorder caused by a fault in a gene in our bodies. The Biotinidase (BTD) gene allows the body to produce the enzyme that separates the essential vitamin, Biotin, to make it available for our body’s metabolism.   We inherit our genes from our parents.  Our bodies are made up of cells.  All of our DNA is in our cells.  Our DNA codes for traits such as eye color, freckles, height, hair color, and even the risk of certain diseases. DNA is made up of building blocks with bases that code for traits.  Portions of DNA make up genes.  Genes can code for proteins involved in producing certain things in our bodies and have lots of different roles, like producing eye color or acting as enzymes, or making all the materials to protect our bodies and so much more. 

DNA is compacted and organized into chromosomes.  We get 23 chromosomes from mom and 23 from dad to make our genetic code.  Biotinidase Deficiency is a recessive genetic disorder which means we inherited the same abnormal gene for the same trait from both mom and dad.  If we received the abnormal gene from just one of our parents and the normal gene from the other, we would be carriers of the disorder without having any symptoms.  The risk of two carrier parents to pass the defective gene on to their children is 25 percent and to have a child who is a carrier is 50 percent, and the chance of not passing on the abnormal gene is 25 percent.  All people carry some type of abnormal genes.  Parents who are close relatives have a higher chance that they both carry that abnormal gene, which increases the risk that the children will have a genetic disorder such as Biotinidase Deficiency.

What problems does it cause? 

Biotin is a B-vitamin that turns proteins, carbohydrates, and fats into the energy our bodies need.  Our bodies need an enzyme that is necessary to be able to use and recycle Biotin. That enzyme is missing in our bodies.  Biotinidase Deficiency is a rare disorder but those who have it may experience symptoms as an infant or later in childhood.  Some of the symptoms are:  loss of hair, speech problems, high levels of acid in blood and urine, seizures, infections, brittle nails, nervous system disorders, delayed development, hearing loss, weak muscle tone, breathing problems, eye or vision problems, neurological issues, learning difficulties, problems with movement and balance, skin rashes, red-eye, drowsiness, diarrhea, vomiting, and even coma.  

These symptoms vary from person to person and not all people with Biotinidase Deficiency will have all these symptoms.  The doctors can’t tell us for sure if some of the difficulties we have had, such as seizures, or our attention deficit, or learning difficulties are caused by Biotinidase Deficiency.  But there is good news.  There is a treatment for it.  Once treatment has started, most symptoms will go away.  Others, such as vision or hearing loss, or learning difficulties may be permanent.

What is the treatment? 

Biotinidase Deficiency can be treated by taking a pill called Biotin.  Because we can’t consume enough Biotin in our food to help with this, we must take this pill.  We will need to take it for the rest of our lives.  It is very important to take it both morning and night so that we don’t develop any of these bad symptoms with our bodies.

How is it diagnosed? 

Biotinidase Deficiency is diagnosed with blood tests.  When “A” was born they tested her blood, and it showed positive for Biotinidase Deficiency.  The hospitals in Utah hadn’t started testing for Biotinidase Deficiency until 2006 and so that is why we didn’t know about it until 2008 when “A” was born.  Because it is a genetic disorder, the three of us were tested for it and the results were positive for all 3 of us.


             Biotinidase Deficiency is a metabolic disorder where the enzyme that processes the vitamin, Biotin, is missing.  There is a solution for it. Taking Biotin can help so that symptoms will disappear or not show up in the first place.  Because of the DNA we inherited from our parents we have this disorder.  We must take Biotin morning and night for the rest of our lives so that our bodies function correctly.

More information

For more information click here or here.


Please leave a comment and let me know if you have had any experience with a rare disorder or anything else you would like to share. Thank you.

2 thoughts on “Biotinidase Deficiency”

    1. merelytenacious

      Thank you. Yes, he did. Sometimes it is hard to understand all the medical, technical stuff. He understands all the genes and DNA type stuff better than I do. It is fascinating, but sometimes really hard to understand.

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