Phosphoglycerate dehydrogenase deficiency (PHGDH deficiency) is a genetic condition where the body can’t make a specific enzyme, leading to a significant decrease in the amino acid serine.
Low serine levels cause various symptoms. The most severe form of this condition is called Neu-Laxova Syndrome.
For PHGDH deficiency, symptoms usually appear in infancy. Babies may have small heads, seizures, and delays in mental and motor skills. Some may also experience issues like congenital cataracts, hernias, anemia, and difficulty feeding. In rare cases, symptoms can start in childhood or adulthood and be less severe. Since this condition is rare, we don’t fully understand all its aspects. Treatment for PHGDH deficiency involves providing extra serine and, in some cases, glycine. Many treated patients see improvements in seizure frequency and well-being. However, this treatment doesn’t seem to help with delays in mental and motor skills. Neu-Laxova Syndrome is generally linked to death before birth. Babies with this syndrome often have small heads, poor growth during pregnancy, scaly skin (ichthyosis), and birth defects in the nervous system, face, and limbs. Most babies with this syndrome are stillborn or pass away shortly after birth. There is currently no treatment available for Neu-Laxova syndrome.
This group of conditions is caused by pathogenic (disease-causing) variants in the PHGDH gene and exhibits autosomal recessive inheritance. This means that both parents must be carriers to have a 25% chance to have a child with the condition. The risk of being a carrier is based on a person’s ancestry or ethnic background. For example, individuals of Ashkenazi Jewish descent have a 1 in 400 chance to be a carrier.