Introduction 

Carpenter syndrome (acrocephalopolysyndactyly type II) is a rare, autosomal recessive disorder caused primarily by mutations in the RAB23 gene. The syndrome is characterised by multisuture craniosynostosis, syndactyly or polydactyly, obesity, and developmental delay. Affected children often exhibit short stature, limb abnormalities, and, in some cases, congenital heart defects or genitourinary anomalies.¹ These multisystemic manifestations significantly impact both nutritional status and endocrine health, making coordinated and individualised care essential for optimal development and quality of life.

Although Carpenter syndrome is rare, insights from the management of other craniosynostosis syndromes (such as Crouzon or Apert syndromes) and skeletal dysplasias help form the foundation for nutritional and endocrine care in these children. Since no universal protocol exists, clinicians must rely on a multidisciplinary, evidence-based approach tailored to each child’s needs.⁴

Nutritional challenges in Carpenter Syndrome

Growth monitoring and weight regulation

One of the primary challenges in Carpenter syndrome is maintaining adequate growth without promoting excessive weight gain. Growth failure may be due to feeding difficulties or high metabolic demands early in life, whereas obesity tends to develop later due to reduced mobility, hormonal dysregulation, or a combination of environmental and physiological factors.¹

Children should undergo regular physical evaluations, including weight, length/height, BMI, head circumference, and mid-upper arm circumference. Growth should be plotted on standardised charts, with syndrome-specific reference curves used where available. When deviations from expected growth trajectories are noted, early intervention is critical to prevent long-term complications.³

Feeding difficulties and nutritional deficiencies

Feeding difficulties in infants with Carpenter syndrome may stem from orofacial anomalies, hypotonia, or coordination problems affecting sucking and swallowing. Oromotor dysfunction is particularly concerning in children with craniofacial abnormalities or neurodevelopmental delay and can lead to insufficient caloric intake and micronutrient deficiencies.

A comprehensive feeding assessment, including input from speech-language pathologists and occupational therapists, is necessary for early identification and intervention. In severe cases, supplemental feeding through nasogastric or gastrostomy tubes may be required to ensure adequate energy and nutrient intake. Enteral nutrition formulas should be age-appropriate and tailored to energy needs, while also accounting for fluid balance, electrolyte levels, and gastrointestinal tolerance.⁷

Risk of obesity and associated complications

Conversely, as children grow older, the risk of obesity becomes more prominent, particularly in those with limited physical activity due to skeletal malformations, low muscle tone, or neurodevelopmental delays.² Obesity not only impacts mobility and self-esteem but also increases the risk of insulin resistance, type 2 diabetes, cardiovascular disease, and early-onset puberty.

Preventative strategies include promoting physical activity within the child's physical abilities, limiting screen time, encouraging sleep hygiene, and fostering healthy eating habits early. Dietary plans should focus on unprocessed, nutrient-dense foods while avoiding high-calorie, low-nutrient foods. Regular counselling by paediatric nutritionists and behavioural support for the family are crucial for sustainable change.^2,6

Endocrine considerations

Growth hormone axis

Short stature may be a consequence of intrinsic skeletal abnormalities or growth hormone (GH) axis dysfunction. Although GH deficiency has not been consistently documented in Carpenter syndrome, other syndromic craniosynostosis cases demonstrate pituitary abnormalities that justify GH evaluation.³ If linear growth is significantly delayed despite adequate nutrition and thyroid function, GH testing should be considered.

In children with confirmed GH deficiency, therapy can improve linear growth, bone mineral density, and body composition. In syndromes with early-onset obesity, GH therapy may also help reduce adiposity and improve lean mass distribution, though careful monitoring is warranted.

Pubertal development

Children with syndromic features are at risk for atypical pubertal timing. Both precocious and delayed puberty have been described in other craniofacial or skeletal syndromes, especially when hypothalamic or pituitary anomalies are present.³

Monitoring the progression of puberty using Tanner staging and assessing bone age can provide early signs of abnormalities. In the case of early puberty, treatment with GnRH analogues may be used to delay further progression, optimise final adult height, and reduce psychosocial stress. Conversely, if delayed puberty is diagnosed, hormone replacement therapy may be necessary.²

Thyroid function and metabolism

Thyroid dysfunction, especially hypothyroidism, should be ruled out in children with growth retardation, cognitive delay, or fatigue.⁴ Routine thyroid function tests (TFTs), including TSH and free T4 levels, should be part of baseline screening, particularly in syndromic patients with delayed development.

Thyroid hormone plays a pivotal role in neurodevelopment, metabolism, and linear growth. If diagnosed, hypothyroidism must be treated promptly with levothyroxine, with regular monitoring of TSH and T₄ levels to ensure appropriate dosing.⁵

Calcium, Vitamin D, and Bone Health

Children with skeletal disorders or reduced mobility are at higher risk for low bone mineral density, osteoporosis, or rickets.⁵^,⁶ Adequate intake of calcium and vitamin D is critical for bone strength, especially during rapid growth phases.

Calcium: Should meet the recommended daily intake based on age. If dietary sources are insufficient (e.g., in lactose-intolerant children), supplements may be necessary.

Vitamin D: Even in sunny climates, deficiencies are common due to limited sun exposure, dark skin, or cultural clothing practices. Supplementation with cholecalciferol may be required, especially during winter months or in children with low dietary intake.

Bone mineral density assessments using dual-energy X-ray absorptiometry (DEXA) may be considered for children with suspected osteopenia or frequent fractures.⁷

Multidisciplinary and individualised management

Team-based care

Given the multisystem involvement in Carpenter syndrome, a multidisciplinary approach is essential. Key team members should include:

• Paediatrician (care coordinator)
• Clinical geneticist
• Paediatric endocrinologist
• Paediatric nutritionist
• Speech-language therapist
• Orthopaedic surgeon
• Craniofacial/plastic surgeon
• Occupational and physical therapists
• Psychologist or social worker

Regular interdisciplinary case reviews allow for integrated care, early identification of complications, and consistent monitoring.⁵

Psychosocial and educational support

Children with Carpenter syndrome often face cognitive delays and learning challenges. Nutritional and endocrine imbalances may exacerbate fatigue, attention difficulties, and behavioural issues. Providing access to early intervention services, individualised education programs (IEPs), and family counselling ensures a supportive environment that fosters optimal development.¹

Recommendations and conclusion

• Growth Monitoring: Perform regular physical measurements, adjust growth expectations using syndrome-specific standards where available¹
• Nutritional Support: Address feeding difficulties early; consider gastrostomy if oral intake is inadequate. Use nutrient-dense diets and monitor for micronutrient deficiencies²
• Obesity Prevention: Establish healthy lifestyle patterns, limit caloric excess, and promote physical activity within the child's functional ability²
• Endocrine Screening: Evaluate for GH deficiency, thyroid dysfunction, and abnormal puberty timing³^,⁴
• Bone Health: Ensure adequate intake of calcium and vitamin D; use supplementation if needed. Consider bone density testing in at-risk children
• Team-Based Care: Maintain ongoing collaboration among specialists to provide holistic, child-centered care^5,7

In conclusion, the nutritional and endocrine management of children with Carpenter syndrome demands proactive, individualised care. Early identification and intervention can mitigate complications, support healthy growth, and improve long-term outcomes. Research into syndrome-specific guidelines and long-term monitoring data is needed to refine care strategies further.