ALG3-congenital disorder of glycosylation

ALG3-congenital disorder of glycosylation is a rare metabolic condition that affects how sugars attach to proteins in the body. This condition is one of several congenital disorders of N-linked glycosylation and is marked by serious neurological challenges such as low muscle tone (hypotonia), developmental delays, intellectual disability, and a smaller head size after birth (postnatal microcephaly). Over time, many people with this condition may also experience gradual loss of brain and cerebellar tissue (atrophy). In addition to these neurological issues, epilepsy, sometimes seen with an abnormal brain wave pattern known as hypsarrhythmia, is frequently reported. Other features that may be observed include difficulties with growth (failure to thrive), joint issues like arthrogryposis multiplex congenita (AMC), vision impairments such as optic atrophy or iris coloboma, and certain facial differences like widely spaced eyes (hypertelorism), a broad nasal bridge, large and thick ears, thin lips, and a small lower jaw (micrognathia).

People with this condition often show signs of low muscle tone, developmental delays, intellectual disability, and postnatal microcephaly. Epilepsy with hypsarrhythmia is frequently seen, along with progressive brain and cerebellar atrophy. Other reported symptoms include failure to thrive, joint contractures (arthrogryposis multiplex congenita), vision problems, and distinct facial features such as a broad nasal bridge and large ears.

This condition is caused by loss of function mutations in the ALG3 gene, which is located on chromosome 3q27.3. ALG3 plays a key role in the process of glycosylation, where sugars are added to proteins to help them function properly. When ALG3 does not work as it should, it disrupts this process, leading to the symptoms seen in this disorder.

Information about treatment is currently limited for this condition.

Information about prognosis is currently limited for this condition.

Information about research is currently limited for this condition.