This article is a correction to the description of a rare case of mosaic partial tetrasomy 18p presenting with oligomenorrhea and intellectual disability. Tetrasomy 18p means four copies of the short arm of chromosome 18. The study analyzed 43 individuals, of which 42 had complete tetrasomy 18p and one also had trisomy of part 18q. Common symptoms included neonatal feeding problems, growth retardation, microcephaly, twitching, muscle tone abnormalities, scoliosis or kyphosis, and brain MRI changes. Other findings included jaundice, respiratory distress, recurrent otitis media, hearing impairment, seizures, refractive errors, constipation, gastroesophageal reflux, cryptorchidism, heart defects, and leg anomalies. In 52% of cases the height was below the 25th percentile and in 19% below the 3rd percentile. Developmental delays and cognitive impairment were present in all individuals.[1][3]