Growth hormone improves social impairments related to genetic disorder known to cause autism

by Bruce Sylvester: Treatment with the growth hormone growth factor-1 (IGF-1) significantly improves social impairment associated with autism spectrum disorder (ASD) in patients with a related genetic syndrome, researchers reported on February 19, 2015 in Pub Med, a public database of biomedical topics maintained by the (US) National Institutes of Health. The study was originally published in the December 12, 2014 issue of Molecular Autism.

“Ours is the first controlled trial of any treatment for Phelan-McDermid syndrome,” said Alexander Kolevzon, MD, Clinical Director of the Seaver Autism Center at the Icahn School of Medicine at Mount Sinai Medical Center in New York City. “Because different genetic causes of ASD converge on common underlying chemical signaling pathways, the findings of this study may have implications for many forms of ASD.”

The investigators evaluated the use of insulin-like growth factor-1 (IGF-1) to treat Phelan-McDermid syndrome (PMS), a condition caused by a deletion or mutation of the SHANK3 gene on chromosome 22. In addition to  developmental and language delays and motor skill deficits, persons with PMS also have autism spectrum disorder.

The authors noted that SHANK3 is significant because of its  role in synaptic function, within the gaps between nerve cells that control whether messages move forward along nerve pathways as they regulate bodily processes.

“Ours is the first controlled trial of any treatment for Phelan-McDermid syndrome,” said Alexander Kolevzon, MD, Clinical Director of the Seaver Autism Center at the Icahn School of Medicine at Mount Sinai Medical Center in New York City. “Because different genetic causes of ASD converge on common underlying chemical signaling pathways, the findings of this study may have implications for many forms of ASD.”

IGF-1 promotes nerve cell survival, synaptic maturation and synaptic plasticity. It is currently approved by the( US) Food and Drug Administration for the treatment of short stature.

Researchers enrolled nine children, aged 5-15, diagnosed with Phelan-McDermid syndrome. The trial had a placebo-controlled, double-blind, cross-over design.

The subjects received three months of treatment with IGF-1 and three months of placebo, in random order.

The investigators reported that, compared to placebo, the IGF-1 phase was associated with significant improvement in social withdrawal and restrictive behaviors as measured by the Aberrant Behavior Checklist and the Repetitive Behavior Scale respectively, both standard behavior scales used to assess treatment effects in ASD.

The authors concluded that this pilot study suggests that IGF-1 is safe, tolerable and associated with significant improvement in both social impairment and restrictive behaviors (fascination with one subject or activity; strong attachment to one specific object; preoccupation with part[s] of an object rather than the whole object; preoccupation with movement or things that move) in subjects with Phelan-McDermid syndrome.

“This clinical trial is part of a paradigm shift to develop targeted, disease modifying medicines specifically to treat the core symptoms of ASD,” says Joseph Buxbaum, PhD, Director of the Seaver Autism Center and Professor of Psychiatry, Genetics and Genomic Sciences and Neuroscience at Mount Sinai. “Results from this pilot trial will facilitate larger studies that more definitively inform efficacy and better targeted therapeutic treatments.”