Overview

A developmental milestone is a specific achievement a child reaches at a certain age, considering normal growth and development. We can ask questions like, When does a child first smile? At what age is it expected that a child start to walk or talk? When we ask these questions, we are interested in knowing which developmental milestones or markers of development were completed. 

There are five domains of concern regarding children’s growth and development: gross motor skills, fine motor skills, speech and language, cognitive, social-emotional and behavioural ¹. Typical milestones happen at two months, four, six, nine, twelve, eighteen, months or over, and the American Academy of Paediatrics recommends screening at ages nine, eighteen, and thirty months².

Why is it so important to detect developmental delays and intervene as soon as possible? The first years of a child’s life can predict their chance of having success as they grow older.¹ For example, a child with a language delay may find difficulties going to school and will need support to learn. Without early support, the learning challenges could reach greater proportions. Healthcare providers are always concerned with and monitoring the child’s healthy growth, to intervene as soon as possible in case a problem is identified.

In this topic, we will explore the main growth and developmental concerns found in children affected by the Ellis-Van Creveld syndrome.

What is ellis-van creveld syndrome (EVC)?

First reported by doctors Simon van Creveld and Richard Ellis in 1940,⁶ Ellis-Van Creveld (EvC) syndrome is a rare genetic condition that can affect the development of cartilages, bones, skin, nails, hair and teeth, growth and various body systems.³ The condition is also referred to as chondroectodermal dysplasia.⁷ Research shows that about 50% of patients do not survive beyond 18 months due to cardiopulmonary complications,⁴ with heart diseases being found in about  66.7% of patients. This condition appears to affect 7 people per 10 million,³ and 250 cases have been documented to date.⁴

What causes ellis-van creveld syndrome (EVC)? 

There are two main genes causing this condition, called EVC and EVC2.¹⁴ Other genes are being linked to different phenotypes, which means how the condition may vary through symptoms. These genes are like workers that translate signals which allow limb development, including arms and legs, as well as the formation of the face and the skull, and the bones that come from cartilage, such as the bones of the hands, the feet, the spine, and other long bones in the body. They also play a role in the development of the teeth and neural cells. Consanguineous marriage also seems to be a risk factor, but it is not the only explanation for the emergence of the syndrome.³

Common symptoms

The severity and type of symptoms may vary between individuals. However, most patients present with a classic triad of features:

• Polydactyly. This is a condition in which a person has more than five fingers on a hand, or postaxial polydactyly, when there are extra toes on the feet.³ In the majority of patients, polydactyly occurs on both hands, whereas approximately one in three patients has polydactyly on their feet⁴
• Ectodermal dysplasia (Dys = wrong/different, Plasia = growth/formation, while ectodermal refers to the layer where the skin and other structures form).³ This medical term means there are abnormalities in nails, hair or teeth
• Short-limb dwarfism,³ meaning that a person’s arms and legs are disproportionately shorter than usual compared to the rest of their body

As mentioned, congenital heart defects are common in EVC syndrome and increase mortality drastically.³ Developmental delay is present in 9% of individuals with the condition.⁵ Moreover, other features can include intrauterine growth delay, underdeveloped lungs known as pulmonary hypoplasia, problems in the urinary tract,⁴ respiratory distress, and auditory issues.⁵

Diagnostic and treatment

Medical professionals combine the physical examination with family history and imaging exams to predict the diagnosis. However, genetic testing is a more secure pathway when the syndrome is suspected. Notice that having a story of the disease in the family increases the risk of contracting it, but not having a family member affected does not exclude the possibility of an EVC diagnosis.⁵

Treatment involves surgery, for example, amputation in cases of polydactyly, and surgical correction of musculoskeletal manifestations.⁴ Moreover, patients may search for orthodontic and/or surgical treatment of dental anomalies, or physiotherapy, occupational therapy, and speech therapy for developmental delay.⁵ In other words, treatment depends on identifying which symptoms are present and involves the entire healthcare team services since early childhood (0-5 years), at early intervention services, from school age and adult healthcare transition preparation. 

Also, having a rare disorder means that the family will need support to set realistic developmental goals, to have access to psychological support, educational advocacy and community resources.¹⁵

Developmental milestones in ellis-van creveld syndrome

Motor development. The development of motor functions often occurs normally in patients with Ellis-Van Creveld Syndrome,⁴ although recent studies also suggest that among the developmental milestones categories, motor skills may be the most affected, possibly secondary to musculoskeletal alterations.⁵ 

Skeletal abnormalities such as knee deformities might cause discomfort/pain, affect mobility, and the ability to walk. Orthopaedic manifestations can negatively impact quality of life.⁷ Despite that, a recent study from Nature Communications observed that polydactyly was associated with a high capacity for motor control, possibly even enhancing an individual's manipulative skills, meaning that each child has to be evaluated individually.⁸ Another finding shows that hand issues do not significantly affect overall motor function, and independent walking may occur between 11 and 35 months; despite delays, patients eventually develop the ability to walk, which is why early support is so important.¹⁰

Physical growth such as limb shortening or disproportionate size can be detected early by ultrasound and corresponds to about one-third of patients.⁵ Children with Ellis-van Creveld syndrome grow more slowly and remain significantly shorter than typical children from infancy through adolescence, and it is expected to stay below average until adulthood.⁹

Language and speech. The manifestations related to the bones of the head and face (craniofacial manifestations) can impact language development; for example, they can interfere with the ability to produce sounds correctly, resulting in communication difficulties. Studies most commonly report that people with oral and facial abnormalities affecting the mouth and teeth, for instance, face feeding difficulties and potentially speech problems.^11,12

Cognitive development. People with EVC typically don't have intellectual disability, and when they do, it is mostly mild to moderate ⁵. However, if there is any suspicion of developmental delay, the primary care provider should be informed. They will have the support of a paediatric care team to educate parents and family on all aspects of development, the syndrome, diagnosis, and prognosis, as well as to offer psychological support and guidance for parents in need.¹³

Socio-emotional and behavioural development. Many children may feel stigmatised due to their physical characteristics, in addition to encountering barriers to their self-esteem, acceptance and social interactions.¹⁶ There is a need for more research investigating how EVC affects people’s lives. 

Summary

Ellis-van Creveld syndrome is a rare genetic condition that affects most physical characteristics and heart health, but it may also impact other body functions. The syndrome is caused by genetic changes before birth. The three main symptoms are having more than five fingers, abnormalities on nails, hair, or teeth, and the limbs developing shorter than normal. The major concern in this condition is the cardiac and respiratory development that may increase the risk of death in infants. The diagnosis is made in a clinic by observing the symptoms and, when possible, genetic testing. The treatment, on the other hand, involves a team of health professionals, such as surgeons, orthopedists, dentists, psychologists, phonoaudiologists, physiotherapists, and occupational therapists. Only a team is ready to provide all the assistance patients may require.

While growth delays are not often seen in this syndrome, it is key to know that they can take place and might need help. Families and professionals need to be prepared to identify children's developmental milestones and to know when to look for expert aid. Also, those with this condition might need changes in day-to-day life; for example, due to short size, they may require interventions for toileting and school activities, as well as psychological support for patients' and families' mental health¹⁷ Information about growth and development in this syndrome is limited; most studies focus on genetics and the most common physical symptoms instead of how these symptoms affect daily life. However, the studies indicate that when developmental problems are present, they are mostly related to motor development, with little impact on cognition or intellect.