ABCD syndrome

ABCD syndrome (Eng. albinism black lock cell migration disorder of the neurocytes, deafness syndrome) is a rare genetically determined congenital disease. It occurs in only about 1 person out of several tens to hundreds of thousands of people. The cause of the disease is a mutation of the EDNRB gene, which may arise randomly during the development of germ cells or the embryo itself. The inheritance pattern is autosomal recessive, which means that two mutated genes are necessary for the symptoms to appear – one from each parent, who are likely healthy carriers.

Symptoms:

The symptoms of the syndrome are already indicated in the name of this syndrome –

• A (albinism)
• B  (black lock)
• C (cell migration disorder)
• D (deafness)

An individual with this diagnosis therefore suffers from various degrees of albinism, which is a condition associated with a lack of skin pigment. As a consequence, there are differently extensive areas of white skin and whitish hair and body hair. In contrast to this, dark thick strands of hair are located above the ears. The disrupted migration (“travelling”) of cells mainly concerns the nerve cells of the digestive system. These cells travel during fetal development into the wall of the digestive tract and ensure its motility. For this reason, people with ABCD syndrome show, from childhood, symptoms of impaired motility of the digestive tract, especially the intestines. Food can therefore become stuck in the intestines, block them, and cause a life‑threatening condition – ileus, which belongs among acute abdominal events.
Abnormalities of the digestive tract also cause difficulties with digestion, and therefore with nutrition and growth. Patients often have hearing impairment, frequently up to a severe degree.

Diagnosis:

Based on the symptoms mentioned above, suspicion may be raised, especially when a newborn with albinism and dark hair strands is observed. The only diagnostic method is genetic testing, which confirms the mutation of the gene.

Treatment:

Similar to most genetic diseases, ABCD syndrome is incurable. Likewise, no prevention for the occurrence of the gene mutation (and the subsequent development of the syndrome) is known. Hearing impairment can be compensated using hearing aids and other assistive devices. In the case of immobility of a part of the intestines associated with blockage by stool, a surgical procedure is necessary to remove the obstructed section.

• nedostatok kožného pigmentu
• belavé vlasy a ochlpenie
• tmavé pramene vlasov najčastejšie nad ušami
• fotofóbia - svetloplachosť
• nystagmus - kmitavý pohyb očných bulbov
• husté vlasy
• problémy s trávením (narušená pohyblivosť tráviaceho traktu, najmä čriev) - znížená peristaltika v dôsledku poruchy inervácie čriev
• v ojedinelých prípadoch môže zhoršená peristaltika viesť k upchatiu čreva - ileus, čo patrí medzi život ohrozujúce stavy
• poškodenie sluchu najčastejšie až ťažkého stupňa (hluchota)