Two distinct phenotypes have been described, depending on the type of variant affecting POLR3GL.
All individuals with biallelic POLR3GL variants share the following features:
• Short stature
• Oligodontia
Individuals with biallelic variants affecting splicing have the following features:
• Endosteal sclerosis (3/3)
• Mild dysmorphisms (3/3) including:
o Upslanting palpebral fissures
o Thin lips
o Downturned corners of the mouth
o Flat philtrum
o Long columella
o Retrognathia
• Motor delay (3/3)
• Club feet (3/3)
• Delayed puberty (2/3)
• Hearing loss (1/3)
• Premature coxarthrosis (1/3)
The only individual with a homozygous loss-of-function variant has the following features:
• Intrauterine growth retardation
• Recognizable dysmorphisms:
o Prominent forehead
o Prominent scalp veins
o Persistent fontanel
o Triangular face
• Significant developmental delay
• Hypotonia
• Mild ventriculomegaly
• Bicuspid aortic valve
• Atrial septal defect type II
• Choanal atresia
POLR3GL