Researchers and editors Randi J Hagerman and Paul J Hagerman have set out to empower readers to be experts on the clinical and biological aspects of fragile X syndrome and have produced a comprehensive addition to the literature about the spectrum of disorders associated with mutations in the FMR1 allele in their book Fragile X Syndrome, and Premutation Disorders. A neurodevelopmental pediatrician and a physician scientist, the doctors Hagerman specialize in the genotypic and phenotypic implications of mutations of the FMR1 allele. The full expression of the FMR1 mutation leads to fragile X syndrome, recognized as the most common inherited cause of intellectual disability with a host of behavioral and physiological manifestations. Fragile X-associated tremor/ataxia syndrome (FXTAS), fragile X-associated neuropsychiatric disorders (FXAND), and fragile X-associated primary ovarian insufficiency are all clinical entities associated with “premutations” in the FRM1 gene. However, in these premutation conditions, the repeat expansion is not as great as in the full fragile X syndrome, and yet, it results in significant medical manifestations.

There are likely two sets of audiences for this book—scientists and physicians are in 1 group, and parents, caretakers, and perhaps those affected by some of the premutation disorders are in the other. Each chapter draws on published literature and has contributions from expert scientists and physicians around the world. Topics include the genetic basis and diagnostic concerns, the developmental and behavioral phenotype, how to manage challenging behaviors, targeted treatment modalities, and the unique medical issues affecting women who carry the fragile X premutation.

As a developmental pediatrician, I would love to be able to recommend this book to all caretakers of people with fragile X syndrome and those affected by related disorders. I expect that reading about the vast developmental and behavioral phenotype affecting those with fragile X and learning about experiences of other affected families would be comforting to the readers who cannot access expert consultation in their community. However, many chapters, including those on diagnostic methods and molecular advances in the field, are geared toward scientific and medical professionals and assume a lot of prior knowledge about laboratory techniques and medical genetics. Of course, it is an option for general readers to skip around within the volume and focus on the sections that are more relevant and perhaps interesting to them.

The chapter dedicated to evidence-based interventions to target the range of behavioral manifestations in the pediatric and adolescent fragile X syndrome population is particularly relevant to families. Challenging behaviors in children can be very distressing, and this chapter provides actionable strategies to empower caretakers to collaborate with a comprehensive team including educators, behavior analysts, physicians, and therapists to manage behaviors at home and in school. It provides theoretical background on behavioral management approaches starting with initial developmental evaluations to understand the child's functional level, strengths, and limitations. It describes analyzing the triggers for and consequences of behaviors to inform a plan of intervention. Included are examples of behavior logs that can be copied to structure observations.

Another accessible chapter makes the case for early detection of fragile X syndrome in the neonatal period through newborn screening and outlines the previous research that has led to understandings of the cognitive, developmental, and behavioral profile of fragile X infants and toddlers. This chapter has the potential to serve as a guide for a very high functioning family that has just received a new diagnosis, or better, to educate pediatricians on how to teach and counsel families on the intricacies of a new diagnosis.

These editors have produced a tremendous reference book for medical professionals on fragile X and related syndromes which promises to inform clinical care of affected families across disciplines. The result reads like a textbook, with gems of knowledge for affected families, if only they can get through it!