Translating knowledge of genetic risk into prevention of speech and language disorders: A pilot study in infants with classic galactosemia

Many children experience severe difficulty learning to produce speech sounds well enough to be understood and to express their thoughts in words and sentences. These disorders, called speech sound disorder and language... [ view full abstract ]

Many children experience severe difficulty learning to produce speech sounds well enough to be understood and to express their thoughts in words and sentences. These disorders, called speech sound disorder and language impairment, respectively, are debilitating in terms of social and educational development. Typically, these disorders cannot be diagnosed until children are old enough to show overt signs, between ages 2 and 4 years. Twin, adoption, and familial aggregation studies have shown that speech and language disorders have a genetic etiology. In those cases where genes and regions of interest have been found, it should be possible in principle to identify infants at risk and to develop earliest and preventative interventions for them. Our study is the first to leverage knowledge of a genetic etiology towards testing a protocol of preventative measures called Babble Boot Camp. Infants with classic galactosemia (CG) are at high risk for severe speech and language disorders. Even during the prespeech stages (cooing, babble), they show very delayed development. In addition, infants with CG are at risk for cognitive delays. The Babble Boot Camp is implemented via parent training by an experienced pediatric speech-language pathologist during infant ages 2 to 24 months. In weekly online meetings, parents learn strategies to foster and support earliest signals of communication (cooing, babble, turn-taking), expand the child’s vocabulary, and increase the child’s sentence length and complexity. Outcome measures include amount of pre-speech vocalizations, number of words understood and produced, general communication competence, cognitive development, and parent and child quality of life. The first cohort of children with CG and a control infant with CG recently turned a year old. The children in the treatment cohort show age-appropriate amounts of speech-like vocalizations, communication behaviors, and emergence of first words, whereas the control infant produces substantially fewer vocalizations and does not yet produce words. A surprising indirect outcome was the fact that the infants in the treatment group showed age-appropriate cognitive development whereas the control infant’s cognitive development was borderline. Together, these results are consistent with a beneficial direct effect of earliest intervention on speech and language development and a beneficial indirect effect on cognitive development. We continue to enroll families and collect data towards validating these early results. Future studies should investigate the effects of the Babble Boot Camp on children’s and parents’ quality of life and the effectiveness of the Babble Boot Camp in children with other types of genetic risk for speech and language disorders.