If your child has cheekbones and a tiny lower jaw at birth, they probably suffer from Nager syndrome. This rare disorder inhibits the normal development of a child’s face, arms, and hands. However, the disease has varying severity and causes feeding problems in infants.
An Overview of Nager Syndrome
Aside from causing underdeveloped cheekbones and jawbones, Nager syndrome can also result in a cleft palate (an opening in your child’s roof of the mouth) and a partially blocked airway. The airway blockage is caused by micrognathia, which causes breathing complications that can be life-threatening.
A child with Nager syndrome will have down-slanting palpebral crevices (eyes that slant downward) and a notch in their lower eyelids (eyelid coloboma). They’re also likely to have no eyelashes. They have abnormally small or deformed ears and are likely to develop hearing problems significantly if their middle ear is affected. The hearing impairment results in delayed speech development. However, this syndrome doesn’t affect a child’s intelligence.
One of the abnormalities of the hands and arms caused by Nager syndrome is absent thumbs. Your child may also have oddly curved fingers (clinodactyly) or fingers that are unusually merged (syndactyly). Since they don’t have enough radius, their forearms are likely to be oddly short, and they have difficulty stretching their elbows.
Sometimes Nager syndrome causes bone deformities in a child’s feet and legs. In rare cases, the affected child may develop genitalia, urinary tract, heart, and kidney abnormalities.
Causes of Nager Syndrome
Some scientists believe that other genes are involved in Nager syndrome. The cause of the other cases is still unknown. The SF3B4 gene instructs the cells to make SAP49 protein, which forms a spliceosome complex. The complex is responsible for processing messenger RNA (mRNA) – a unique chemical related to DNA that works as the genetic design for producing proteins.
Mutations in the SF3B4 gene hinder the production of functional SAP49 protein, leading to Nager syndrome. Lack of this protein in your body prevents the formation of spliceosomes, thus impairing the processing of mRNA and altering the process of developing different body parts. It can also ruin BMP conduit signaling, resulting in the abnormal development of particular body parts.
Treatment
Nager syndrome is treated through coordinated efforts of various specialists, including pediatricians, plastic surgeons, ear, nose, and throat specialists, and oral surgeons. This treatment involves surgery to rectify the abnormalities.
