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Madisons Foundation - Moms And Dads In Search Of Needed Support

Biotinidase Deficiency
Monday, 02 February 2004
Tuesday, 23 November 2004
infantile multiple carboxylase deficiency, juvenile carboxylase deficiency, late-onset multiple carb

What

Biotinidase Deficiency (BD) is caused by the lack of an enzyme (biologically active protein) called biotinidase. Biotinidase functions to maintain normal levels of a protein called biotin. Biotin plays a critical role in preserving proper body metabolism which is the molecular activity within all the body tissues. Without treatment, this disorder can lead to seizures, developmental delay, eczema (itchy rash), and hearing loss.

Who

The gene defect responsible for biotinidase deficiency is usually inherited in a recessive manner. A child must receive two copies of the faulty gene to develop the disease. Males and females are equally affected and there is no racial preference. The estimated frequency of biotinidase deficiency is 1 in every 60,000 live births.

Signs and Symptoms

Children with biotinidase deficiency appear normal at birth, but develop symptoms after the first weeks or months of life. They may have some or all of the following symptoms: • Hypotonia (weak muscles) • Ataxia (uncoordinated movements) • Seizures • Developmental delays • Alopecia (hair loss) • Seborrheic dermatitis (inflammatory skin rash) • Hearing loss • Optic nerve atrophy (wasting) leading to vision impairment • Recurrent fungal infections from the weakened immune system. • Breathing difficulties from affected regions of the brain.

Possible Causes

The condition is caused by a defective gene that prevents normal production of the enzyme biotinidase.

Diagnosis

Twenty-three (23) states currently have a newborn screening program that includes testing for biotinidase deficiency (as of September 2001). The newborn screening test (NBS) involves obtaining a few drops of blood before the baby is sent home from the hospital. If this test is positive or suspicious for biotinidase deficiency, your baby’s doctor will usually perform additional blood tests screening for other metabolic disorders. If seizures are present, an electroencephalogram (EEG) or electrical “brain wave” test will be helpful and imaging studies such as a CT or MRI scan are ordered to determine if there is any structural brain abnormality.

Treatment

Biotinidase deficiency is treated with daily biotin supplements, which can help clear the skin rash, reverse the hair loss, and improve the neurological status in children who are diagnosed early. The dosage will depend on the severity of the deficiency.

Prognosis

With early diagnosis and treatment, permanent neurologic damage can be prevented. However, in patients who have severe biotinidase deficiency and experience a delay in diagnosis, permanent neurological damage in the form of blindness and deafness does occur.

Connect with other parents

In the spirit of community and support, Madisons Foundation offers the unique service of connecting parents of children with rare diseases. If you would like to be connected to other parents of children with this disease, please fill out this brief form.

Weblinks

Save Babies Through Screening
Well organized website devoted to educating the public.

William s Story
Inspiring story that brings hope to families

Mericon Industries
Practical discussion on issues that parents face.

Connecticut Children s Medical Center
Well organized pamphlet on the condition.

Newbornscreening.com
Information for those interested in the newborn screening process

Google Search for Biotinidase Deficiency

References and Sources

EMedicine : article by Difazio M. http://www.emedicine.com/PED/topic239.htm Author unknown, (2004) Biotinidase deficiency. In: Behrman RE, Kliegman RM, Jenson HB (eds), Nelson Textbook of Pediatrics, 17th ed. WB Saunders, p 412-413.