Sotos syndrome and scoliosis surgical treatment: a 10-year follow-up

Abstract

Sotos syndrome is caused by a gene deletion with an autosomal dominant pattern of inheritance. Cerebral gigantism, hypotonia and joint hyperextensibility are characteristic features of this syndrome. A percentage of these patients develop progressive scoliosis early in life. In the literature, few studies on the evolution of scoliosis in Sotos syndrome have been published. We retrospectively evaluated eight patients diagnosed with Sotos syndrome and scoliosis treated at the Garrahan Children Hospital between 1988 and March 2009. Clinical charts and imaging studies were assessed. Eight patients (19%) presented with scoliosis and seven of them (87.5%) required surgical treatment. The mean follow-up was 9.5 years (range 3-18). Mean age at first consultation was 5.2 years (range 1.1-11.2). Mean Cobb angle for scoliosis at first consultation was 34.3° (range 20°-42°) and the mean Cobb angle for kyphosis was 45.6° (range 30°-90°). Mean age at surgery was 11.2 years (range 3.7-18.10). The surgical procedures performed were instrumented posterior arthrodesis, alone or combined with anterior arthrodesis, instrumented anterior arthrodesis, while one patient is currently in treatment with growing rods. Preoperative mean Cobb angle for scoliosis was 72.3° (range 54°-130°) and for kyphosis was 59.8° (range 30°-108°); postoperative mean Cobb angle for scoliosis was 45.5° (range 6°-90°) and for kyphosis was 40.2° (range 30°-80°). There were three early complications (pleural effusion in two cases and death due to sepsis in one) and two late complications (kyphosis above the instrumentation area and dislodgement of the proximal hooks). Incidence of scoliosis in Sotos syndrome is high and thus close monitoring of patients with Sotos syndrome during growth is important for early detection of this entity. Joint hyperextensibility and hypotonia that are characteristic of the syndrome should be considered at the moment of surgery to avoid short fusions.

The Association of Scoliosis and NSD1 Gene Deletion in Sotos Syndrome Patients

“…Scoliosis is recognized to be a common symptom associated with Sotos syndrome, with Sotos et al reporting a case with mild scoliosis in their original series of five patients 16 and confirming the association in a later report 12–16 . Although the causes or factors that predispose Sotos syndrome patients to scoliosis remain unknown, scoliosis has been observed in approximately one-third of patients with variable severity 1 .…”

“…1 Scoliosis is recognized to be a common symptom associated with Sotos syndrome, with Sotos et al reporting a case with mild scoliosis in their original series of five patients 16 and confirming the association in a later report. [12][13][14][15][16] Although the causes or factors that predispose Sotos syndrome patients to scoliosis remain unknown, scoliosis has been observed in approximately one-third of patients with variable severity. 1 Examination into the genetic background of the 25 scoliosis patients with NSD1 aberrations in this study revealed that the 20 patients with microdeletions had more prominent and progressive scoliosis compared to the five patients with mutations.…”

“…11 Although scoliosis has been reported in approximately 30% of Sotos syndrome patients, 1 the genetic background of this associated symptom has not been sufficiently studied. There are reports maintaining that scoliosis develops at early ages with severe and rapidly progressive curves, [12][13][14][15] whereas others state that scoliosis is rare and variable in severity, ranging from mild scoliosis requiring no intervention to severe scoliosis requiring bracing or surgery. 16,17 In the present study, we analyzed the NSD1 gene disruptions in 63 Sotos syndrome patients at a single center and examined the correlation between the NSD1 abnormality and scoliosis.…”