CLINICAL REPORT Guidance for the Clinician in Rendering Pediatric Care Health Supervision for People With Achondroplasia Julie Hoover-Fong, MD, PhD, FACMG,a Charles I. Scott, MD, FAAP,b Marilyn C. Jones, MD, FAAP,c COMMITTEE ON GENETICS Achondroplasia is the most common short-stature skeletal dysplasia, abstract additionally marked by rhizomelia, macrocephaly, midface hypoplasia, and aGreenberg Center for Skeletal Dysplasias, McKusick-Nathans normal cognition. Potential medical complications associated with Department of Genetic Medicine, Johns Hopkins University School of b achondroplasia include lower extremity long bone bowing, middle-ear Medicine, Baltimore, Maryland; Nemours/Alfred I. duPont Hospital for Children and Sidney Kimmel Medical College, Thomas Jefferson dysfunction, obstructive sleep apnea, and, more rarely, cervicomedullary University, Wilmington, Delaware; and cDepartment of Pediatrics, compression, hydrocephalus, thoracolumbar kyphosis, and central sleep University of California, San Diego and Rady Children’s Hospital, San Diego, California apnea. This is the second revision to the original 1995 health supervision guidance from the American Academy of Pediatrics for caring for patients with Drs Hoover-Fong and Scott wrote new content and edited content from the previous AAP statement and responded to reviews; Dr Jones achondroplasia. Although many of the previously published recommendations provided editorial and content review, shepherded the document through multiple stakeholders review, and addressed specific remain appropriate for contemporary medical care, this document highlights concerns; and all authors approved the final manuscript as submitted. interval advancements in the clinical methods available to monitor for Clinical reports from the American Academy of Pediatrics benefit from complications associated with achondroplasia. This document is intended to expertise and resources of liaisons and internal (AAP) and external reviewers. However, clinical reports from the American Academy of provide guidance for health care providers to help identify individual patients Pediatrics may not reflect the views of the liaisons or the at high risk of developing serious sequelae and to enable intervention before organizations or government agencies that they represent. complications develop. The guidance in this report does not indicate an exclusive course of treatment or serve as a standard of medical care. Variations, taking into account individual circumstances, may be appropriate. All clinical reports from the American Academy of Pediatrics automatically expire 5 years after publication unless reaffirmed, The original “Health Supervision for Children with Achondroplasia” policy revised, or retired at or before that time. from the American Academy of Pediatrics (AAP) in 1995 provided useful This document is copyrighted and is property of the American Academy of Pediatrics and its Board of Directors. All authors have filed management recommendations to pediatricians caring for children with conflict of interest statements with the American Academy of achondroplasia from birth through early adulthood.1 The first revision in Pediatrics. Any conflicts have been resolved through a process approved by the Board of Directors. The American Academy of 2005 expanded the scope of the document to include new information Pediatrics has neither solicited nor accepted any commercial about the molecular genetics of achondroplasia and improvements in involvement in the development of the content of this publication. anticipatory guidance in terms of prevention and treatment of DOI: https://doi.org/10.1542/peds.2020-1010 complications of the condition.2 The majority of the information provided Address correspondence to Julie Hoover-Fong, MD, PhD. E-mail: in those documents remains pertinent and accurate in the current care [email protected] of patients with achondroplasia. This revision highlights additional PEDIATRICS (ISSN Numbers: Print, 0031-4005; Online, 1098-4275). interval advancements in the clinical methods available to monitor for Copyright © 2020 by the American Academy of Pediatrics complications associated with achondroplasia, including adult health complications that may be rooted in childhood and should, therefore, be monitored and managed from birth. This document also incorporates To cite: Hoover-Fong J, Scott CI, Jones MC, AAP COMMITTEE a few of the more recent treatment options for achondroplasia to provide ON GENETICS. Health Supervision for People With Achondroplasia. Pediatrics. 2020;145(6):e20201010 an informational core from which the general pediatrician can explore Downloaded from www.aappublications.org/news by guest on September 24, 2021 PEDIATRICS Volume 145, number 6, June 2020:e20201010 FROM THE AMERICAN ACADEMY OF PEDIATRICS additional resources with patients. mutation in the fibroblast growth to 135 cm (4–4.5 ft) (Fig 1).16 The The authors recognize the audience factor receptor type 3 (FGFR3) gene most common complication, for this document may have variable in that affected individual.3,5,6 occurring in adulthood, is related to medical resources at their disposal to Because virtually all of the causal lumbosacral spinal stenosis with monitor and treat patients with mutations occur at exactly the same compression of the spinal cord or – achondroplasia. The intent of this nucleotide within the gene,6 genetic nerve roots.17 19 This complication is consensus document is to provide testing for achondroplasia is usually treatable by surgical guidance that may be adapted to each straightforward. It is not necessary to decompression, with less sequelae if individual patient in his or her unique perform molecular testing in every treated at an early stage. Most environment. Children and child with a clinical diagnosis of children with achondroplasia do well. adolescents with achondroplasia achondroplasia. However, FGFR3 However, children affected with should have care coordinated through testing should be considered when achondroplasia commonly have a medical home; however, some of a confirmed achondroplasia diagnosis delayed motor milestones the surveillance and counseling is needed. For example, infants or (Fig 2),20–22 otitis media, and bowing suggested in this document will be children with an atypical of the lower legs.23 Less commonly, provided by a number of specialists achondroplasia presentation may infants and children may have serious 7 with expertise in the management of have a second genetic condition. health consequences related to achondroplasia, if these individuals Such children also should be referred craniocervical junction compression are available. for clinical genetics evaluation. because of a relatively small foramen Different mutations in the FGFR3 Achondroplasia is the most common magnum, hydrocephalus, upper- gene can also cause 2 other short condition associated with severe, airway obstruction, or thoracolumbar stature dysplasias: disproportionate short stature, with kyphosis. Although they are less hypochondroplasia and an estimated birth incidence of 1 in common, anticipatory care should thanatophoric dysplasia. A child with 10 000 to 1 in 30 000.3,4 There include identifying children at highest hypochondroplasia has the same is no recognized ethnic or sex risk and intervening to prevent clinical features as one with predisposition. The diagnosis can potentially serious sequelae. Most achondroplasia, as listed above, but usually be made on the basis of individuals with achondroplasia are milder overall. Growth hormone clinical characteristics and specific of normal intelligence and are able to therapy may be considered as features on radiographs, including lead independent and productive a treatment option for those with a square shape of the pelvis with lives.24 Because of their hypochondroplasia, but it has not a small sacrosciatic notch, short disproportionate short stature, been shown to be effective in pedicles of the vertebrae with – however, a number of psychosocial patients with achondroplasia.8 11 interpedicular narrowing from problems can arise.25 Chronic pain, Thanatophoric dysplasia usually can the lower thoracic through lumbar a problem that may begin in be distinguished from achondroplasia region, rhizomelic (proximal) childhood and magnify into and hypochondroplasia because shortening of the long bones, adulthood without intervention, may severe thoracic and lung hypoplasia proximal femoral radiolucency, and be playing a larger role in overall life are expected to be lethal in the pre- or a characteristic chevron shape of the 12 satisfaction and coping than has been early postnatal period in the former. distal femoral epiphyses. Other 26 Rare exceptions of a patient with previously appreciated. Further clinical features include short stature, thanatophoric dysplasia surviving are investigation is needed to better macrocephaly (absolute and relative), reported but only with aggressive understand the temporal relationship trident configuration of the hands, measures of resuscitation at delivery among pain, function, and medical or and long, near-normal-length trunk. and significant respiratory support surgical treatment to allow for the Achondroplasia is an autosomal thereafter.13,14 Age-specific highest quality of life possible. fi dominant disorder, meaning a person recommendations pertaining to Families can bene t from anticipatory with achondroplasia has a 50% genetic counseling and testing are guidance and the opportunity to learn chance of passing the condition