Helping parents of children with monogenetic disorders understanddevelopmental trajectories: lessons from achondroplasiaMICHAEL E MSALLKennedy Research Center on Intellectual and Developmental Disabilities, University ofChicago, Comer Children's Hospital, Chicago, IL, USA.

doi: 10.1111/j.1469-8749.2012.04267.x

This commentary is on the original article by Ireland et al. on pages 532–537of this issue.

Over the past four decades, major molecular advances, cou-pled with advances in the biology of somatic growth, haveimproved our understanding of children with skeletal dyspla-sia, the most common phenotype of which is achondroplasia(OMIM 100800).1 This autosomal dominant disorder iscaused by mutations of the transmembrane receptor fibroblastgrowth factor receptor 3 (FGFR3) gene, a regulator of endo-chondral ossification. The creation of clinical centers of excel-lence involving genetics and orthopedics (with access to othermedical, psychological, and rehabilitation services) hasimproved our management of secondary complications anddeformities.2 However, there is an additional need to formclinical networks with uniform protocols to better implementinterventions that monitor for serious complications, educatefamilies, and support children. Such measures would enablethe children to live fully with a genetic difference and notexperience life as one of missed opportunities or stigma.3 It iswith this latter need that the paper by Ireland et al. 4 providescritically important information for physicians, education andrehabilitation professionals, and families.

Forty-eight families from Australia and New Zealand withchildren born in the last decade were prospectively studied every3 months to understand gross motor, fine motor, communica-tion, and feeding skills. In addition, this representative cohort(96% of eligible families consented to participate) had the bene-fit of the preventative recommendations to restrict early sittingso as to minimize risks for thoracolumbar kyphosis. The investi-gators linked their observations to the Personal Health RecordBook used for children throughout Australia to document theirgrowth and development. Several findings deserve emphasis.

Though motor delays in crawling and walking independentlyoccurred, the median age of attainment of commando crawlingoccurred at 9 months and walking independently occurred at19 months. These findings reflect that self-mobility for explor-ing the environment was occurring throughout the first 2 yearsof life. Importantly, changing from sit to stand and standingwith support were attained at ages similar to non-affected peers.

Some unique transition strategies for floor mobilityoccurred as an alternative to traditional crawling. Snowploughing or bear walking occurring in more than half, while

100% did commando crawling and 31% did traditionalquadruped crawling. Fine motor and gesture communicationskills were similar to typically developing peers.

Because of midface hypoplasia, 33% received middle eartubes. There was a wide range of expressive language develop-ment with median ages for single words at 18 months, com-bining two words at 24 months, and speaking in shortsentences at 27 months. The lesson here is that developmentalsurveillance across all streams of development includingspeech-language skills is important.

During their first 18 months, children’s social skills, cup-drinking, eating smooth and mashed solids, finger feeding,and spoon use progressed similar to peers. The elegant andwell-illustrated Figure 1 displays these milestones across bandsfor the 25th to 50th centile, 50th to 75th centile, and 75th to90th centile. This graph will help health professionals andfamilies understand their children’s profile of gross and finemotor, communicative, and feeding skills.

Importantly, combining these milestones with the healthchecklist and the individualized height, weight, and head cir-cumference curves of Trotter and Hall will allow better coor-dination across systems of care.3

Additional tables for complex self-care (dress, bathe,groom), social-communicative, and functional motor skills forchildren aged 3–7 years with achondroplasia were illustratedin a previous study.5 By combining our understanding of thesedevelopmental trajectories, health and rehabilitation profes-sionals can devise strategies that promote independence, cele-brate accomplishments, lessen family fears, and address socialisolation. Family support groups in Australia (http://www.sspa.org.au/), the UK (http://www.restrictedgrowth.co.uk),and the USA (http://www.lpaonline.org) are essential andvaluable partners in these undertakings. By emphasizing par-ticipation over social isolation, we can also begin to under-stand some of the missed opportunities that lead to the highrates of cardiovascular morbidity that occur in adults withachondroplasia.6 Using this framework of enablement, we willbe better prepared for the translational research interventionsthat will attempt to decrease the long-term consequences ofthe gain in function mutation in the FGFR3 gene.

ACKNOWLEDGEMENTDr Msall is supported in part by T73 MC11047 HRSA – Department

of Health and Human Services Leadership Education in Neurodevel-

opmental and Related Disorders Training Program (LEND) and P30

HD054275 NIH ⁄ NICHD J.P. Kennedy Intellectual and Develop-

mental Disabilities Research Center (IDDRC).

488 Developmental Medicine & Child Neurology 2012, 54: 484–491

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Active head lifting from supine in infancy: a significant stereotypy?MIJNA HADDERS-ALGRADepartment of Paediatrics – Developmental Neurology, University Medical CenterGroningen, University of Groningen, Groningen, the Netherlands.

doi: 10.1111/j.1469-8749.2012.04237.x

This commentary is on the original article by van Haastert et al. on pages538–543 of this issue.

Van Haastert et al.1 are the first to report that active head liftingfrom supine (AHLS) in infants who had been admitted to theneonatal intensive care unit is associated with less favourablecognitive development in the second year of life. This is anintriguing observation which needs to be studied in more detail.

Interestingly, AHLS is one of the items of the Gross MotorFunction Measure (GMFM),2 where it is regarded as a posi-tive sign. But of course, it is important to realize that theGMFM has been designed to evaluate motor behaviour inchildren with an established diagnosis of cerebral palsy, imply-ing that these children are usually older than 2 years. It is con-ceivable that AHLS in children with cerebral palsy older than2 years is a favourable sign.

AHLS is a spontaneous motor activity which emergesbetween 10 and 16 weeks postmenstrual age. Thereafter itcontinues to be part of the typical fetal motor repertoire.3

After birth, when the newborn infant is exposed to the forcesof gravity, the ability to lift the head in supine is no longerpresent. AHLS re-emerges around 3–4 months post-term, butonly in a minority of infants (M Hadders-Algra, personalobservation 2011).

In the study population van Haastert et al.1 describe,AHLS was often combined with extension and adduction ofthe legs with the ankles in plantar flexion and clawing of thetoes. They mention the resemblance of the AHLS pattern to

the symmetric tonic neck reflex (STNR). The STNR wasdescribed by Magnus and de Kleijn4 on the basis of experi-ments with decerebrate cats: excitation of neck propriocep-tors induced by anteflexion of the neck results in extensionof the legs. It is, however, questionable whether STNR-activity is part of typical human motor development.5

STNR-activity may be present in children with cerebralpalsy, but its significance in these children has also long beendisputed.6

The invariable combination of AHLS with extension andadduction of the legs, plantar flexion of the ankles, and clawingof the toes reported by van Haastert et al.1 suggests the pres-ence of stereotyped behaviour. Stereotyped motor behaviourimplies reduced variation in motor behaviour. A reducedmotor repertoire, including a reduced repertoire of posturaladjustments, has been associated with lesions of the periven-tricular white matter, i.e. with reduced cerebral connectivity.7,8

Currently, it is increasingly recognized that reduced intra- andinterhemispheric connectivity may be one of the neural seque-lae of preterm birth – sequelae which are associated with lessoptimal cognitive performance.9

In order to improve our understanding of AHLS we needto study: (1) the prevalence of AHLS in the general popula-tion; (2) the strength of the association of AHLS with theextension pattern of the legs; (3) the neural substrate of AHLSusing advanced magnetic resonance imaging; and (4) the rela-tion of AHLS with cognitive function at school age andbeyond. For the time being, clinicians in charge of follow-upof graduates of the neonatal intensive care unit should care-fully monitor cognitive development and leg extension pat-terns in infants who present with AHLS.

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Active head lifting from supine in early infancy: an

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tremitatenmuskeln von der Kopfstellung. Pflugers Archiv

1912; 145: 455–548.

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cardo PJ. Primitive reflex profile: a quantitation of primitive

reflexes in infancy. Dev Med Child Neurol 1984; 26: 375–83.

6. Bobath K. A neurophysiological basis for the treatment of

cerebral palsy. Clinicals in Developmental Medicine No.

75. London: Spastics International Medical Publications

Mac Keith Press, 1980.

7. Hadders-Algra M, Brogren E, Katz-Salamon M, Forssberg

H. Periventricular leukomalacia and preterm birth have dif-

ferent detrimental effects on postural adjustments. Brain

1999; 122: 727–40.

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