Mosaic Turner syndrome with improved Chiari type 1 malformation after growth hormone therapy: A case report

We described a three-year-old girl whose Chiari type 1 malformation associated with mosaic Turner syndrome disappeared after GH therapy. She was diagnosed with mosaic Turner syndrome at the age of 1 yr and 7 mo by a chromosomal analysis (G-band) for short stature and was treated with GH. Sagittal T1-weighted magnetic resonance imaging (MRI) performed before the start of GH demonstrated herniation of the cerebellar tonsils 7 mm below the foramen magnum into the cervical spinal cord. After the initiation of GH therapy, the growth in height was favorable and improved from 70.6 cm (–3.5 SD) to 92 cm (–1.5 SD) in 2 yr. An MRI examination 19 mo later showed the disappearance of Chiari type 1 malformation. GH therapy either exacerbates or ameliorates Chiari type 1 malformations associated with GH deficiency (GHD). Since Turner syndrome uses more GH than GHD, careful follow-up is required if the disease is associated with Chiari type 1 malformation.