GGC Paediatric Guidelines
- Genetic counselling should be provided for the family to understand the implications, inheritance patterns and potential for recurrence in future pregnancies. This may useful both antenatally and postnatally.
Achondroplasia, investigation & management with neonates with suspected achondroplasia
Warning
Objectives
- To identify which initial investigations should be carried out prior to discharge from the NICU.
- To highlight the specialties to whom onward referral should be made in infants who have a clinical or genetic diagnosis of achondroplasia.
- To provide information on follow up for infants with achondroplasia and health surveillance in the first year of life.
- To highlight advice, resources, and support available for parents and carers of infants with achondroplasia.
Audience
This guideline is applicable to neonatal staff working with neonates in the West of Scotland managed clinical network. This guideline is intended to provide guidance on the investigation and management of babies born with suspected achondroplasia.
Achondroplasia is the most common form of disproportionate short stature, with reported incidence from 1 in 10,000 to 1 in 30,000 live births and affecting over 250,000 people worldwide. Achondroplasia is caused by a genetic mutation which decreases chondrocyte proliferation with consequent reduction in endochondral bone formation resulting in the observed proximal limb shortening. The main clinical features typically seen in achondroplasia are: disproportionate short limbs when compared to the trunk, macrocephaly with frontal bossing, and ‘trident’ shaped hands. Typical radiographic findings include squaring of the pelvis, ‘chevron shape’ on distal femoral epiphyses, and small vertebral pedicles. Diagnosis can be confirmed by genetic testing.
A genetic diagnosis is made by testing for a mutation in the Fibroblast Growth Factor Receptor 3 (FGFR3) gene, with 99% of cases being caused by a Gly380Arg substitution. Around 75% of children with achondroplasia are born to two parents of average stature, representing a de novo mutation. There are several complications associated with achondroplasia, including increased incidence of sleep-related disordered breathing, hearing loss, and narrowing of the foramen magnum. Parents should be given advice and information on these aspects, as well as other aspects of the development and care of children with achondroplasia.
- Infants should have a clinical examination of the respiratory system shortly after delivery, and oxygen saturations checked if any concerns.
- Prior to discharge, children with achondroplasia should have a car seat challenge to assess for sleep-related breathing disorders (discuss with neonatal team, as per local protocol for car seat challenge.)
- Where there are concerns related to breathing during sleep, or abnormal car seat challenge, refer to respiratory team for overnight oximetry and respiratory study as an in-patient.
- In infants with no concerns identified, arrange for overnight oximetry study within the first 3 months and make an outpatient respiratory referral.
- Continue to monitor for sleep-related disordered breathing, with 6-12 monthly pulse oximetry until age 5 years.
- Advise parents that most children with achondroplasia snore, and to observe for other features of obstructive sleep apnoea, including intermittent breathing, choking, glottal stops, or deep compensatory sighs.
- It is recommended to perform a cranial ultrasound for all infants with achondroplasia before discharge to detect any signs of hydrocephalus and assess the ventricles.
- If ultrasound does not indicate any abnormalities, MRI should be performed within three months to provide a more detailed assessment of the brain. MRI brain and spine should be requested to look for craniocervical junction stenosis.
- If ultrasound indicates any abnormalities such as hydrocephalus, then results may be discussed with neurosurgical team and further imaging arranged.
- Prior to discharge parents should be informed about the expected growth pattern for children with achondroplasia; the importance of regular followup with healthcare providers should be emphasised to monitor weight and length.
- Prior to discharge parents should be provided with the copy of an appropriate achondroplasia growth chart to be added to their red book for monitoring of growth in the community (see Appendix 1).
- Regular follow up every one or two weeks with health visitors should be organised to measure child’s head circumference in the first six months of life. Health visitors should be advised to contact neonatal team in the first instance if there are any concerns.
- Parents should be provided with information about average expected time for developmental milestones for children with achondroplasia and be advised that it is often delayed in comparison to children without achondroplasia (see Appendix 2).
- Parents should be provided with guidance on positioning and handling, adaptive equipment, and activities to support their child's development (e.g. choosing appropriate car seat). (See Appendix 2).
- Physiotherapy can help to address motor development issues. The referral is expected to be made by the bone clinic based on child’s individual needs.
- A referral to Glasgow Children’s Hospital Achondroplasia MDT clinic on discharge is recommended to provide ongoing care.
- Ensure universal newborn hearing screening programme is performed within first four weeks and results reviewed, with audiology follow-up arranged if necessary.
- Formal behavioural audiometric assessment is recommended to be carried out by 9-12 months.
- It is recommended that formal hearing assessment is carried out routinely for children with achondroplasia, ideally annually, and care established with an ENT surgeon if required.
- Children residing within NHS Greater Glasgow and Clyde should be referred to audiology to take part in Annual Hearing Screening Programme for Children with Achondroplasia. Local arrangements may exist for children in other health boards.
- Advise parents on the risk of serous otitis media secondary to short Eustachian tubes and recommend ear examination is indicated in presence of ear pain, or any persistent upper respiratory tract infection.
- Any child with language delay should have a chronic serous otitis media and resulting conductive hearing loss excluded.
- Families of the infants affected with achondroplasia should be offered guidance and counselling in order to provide them with appropriate emotional and informational support and help to navigate potential challenges
- Functional difficulties and potential challenges should be discussed, while emphasising that most people with achondroplasia can live self-sufficient lives.
- The infant's family should be offered psychological and social support to address their concerns and provide them with coping strategies.
- Involvement in support groups or organizations specialising in achondroplasia should be encouraged (e.g.: https://www.dsauk.org/, https://littlepeopleuk.org/, https://rgauk.org).
Male charts
Height for males with Achondroplasia
Height by weight standards for males with Achondroplasia
Weight for age curves for males with Achondroplasia (0-36 months)
Weight for age curves for males with Achondroplasia (2-16 years)
Head circumference for males with Achondroplasia
Female charts
Height for females with Achondroplasia
Height by weight standards for females with Achondroplasia
Weight for age curves for females with Achondroplasia (0-36 months)
Weight for age curves for females with Achondroplasia (2-16 years)
Head circumference for females with Achondroplasia
Height for males with Achondroplasia
Height by weight standards for males with Achondroplasia
Weight for age curves for males with Achondroplasia (0-36 months)
Weight for age curves for males with Achondroplasia (2-16 years)
Head circumference for males with Achondroplasia
Height for females with Achondroplasia
Height by weight standards for females with Achondroplasia
Weight for age curves for females with Achondroplasia (0-36 months)
Weight for age curves for females with Achondroplasia (2-16 years)
Head circumference for females with Achondroplasia
