Abstract

Ellis-Van Creveld syndrome (EVC), also called chondroectodermal dysplasia, is a rare disorder where people are born with smaller bodies, extra fingers (polydactyly), chest issues, as well as skin, hair, or nail problems. This condition comes from variants in the EVC and EVC2 genes, which make proteins needed for important body signals, such as skeletal morphogenesis. The most significant changes are seen in the limbs and thorax. These changes shape how a person looks and bring big health risks, which can affect how long they live and how well they can get back to good health. This article talks about the range of limb and thoracic changes in EVC, what causes them to develop, and why they are important for gauging the progression of this disease, handling it, and knowing what might happen next.

Introduction

Ellis-Van Creveld syndrome was first noted in 1940, and is part of the group of short-rib thoracic dysplasias (SRTDs).¹ The syndrome is seen in less than 1 out of 60,000 newborns but shows up more in some old groups, like the Old Order Amish in Pennsylvania.²

The hallmark features of EVC are:

• Disproportionate short stature, mainly in the arms and legs
• Postaxial polydactyly in the hands
• Thoracic narrowing from short ribs
• Ectodermal dysplasia affecting teeth, nails, and hair
• Congenital heart defects occur in about 60% of people³

Out of these, the issues with limbs and chest are key as they determine how an individual appears, breathes, and moves. Identifying these signs is key for quick diagnosis of the problem before full care can be provided.

Limb abnormalities in Ellis-Van Creveld syndrome

1. Shortening of Limbs

• Phenotype: People show a big lack of height with notable shortness in the mesomelic (forearms and lower legs) and acromelic (hands and feet) parts of the body
• Pathophysiology: Hedgehog signals mess up the bone growth in growth plates, making chondrocytes grow too fast and therefore cause bones to be shorter⁴
• Clinical implications: Lack of growth is clear from a young age and lasts into adolescence. Full height is mostly between 110–160 cm. While not deadly, the shortness adds to psychological stress and might limit job choices

2. Polydactyly

• Characteristic feature: Most people with this condition have an extra finger on the edge of their hand
• Diagnostic value: If someone has this extra finger and is much shorter than usual, it's a strong sign they might have EVC
• Management: Doctors usually fix this with surgery when the child is young, for both use and visual looks

3. Hand and foot dysplasia

• Hands: Wide hands with short bones in the palm and oddly shaped bone ends are common
• Feet: More toes than usual might show up on the feet, but it's rarer than on the hands
• Radiological findings: X-rays show abnormal areas of bone formation, irregular bone ends in fingers, and bones that have grown together

4. Joint deformities

• Valgus deformities of the knees and ankles can happen from bones not lining up properly
• Implications: The structural abnormalities can affect how you walk, and you might need to check in with a specialist doctor
• Interventions: Using supports, shaping bone surgery, and therapy are ways to help you move more efficiently

5. Functional limitations

• Not being able to move as much, mainly in the wrists and fingers, can impact small, detailed movements
• Pain in muscles, bones, and early joint wear might contribute to long-term issues

Thoracic abnormalities in Ellis-Van Creveld syndrome

1. Narrow thorax

• Phenotype: The ribs are short and run side to side, leading to a thin, bell-shaped chest
• Pathophysiology: Poor growth of ribs, as bad cell growth stops the chest from getting bigger
• Clinical impact: Hard breathing is a big risk for newborns and young kids. Small lungs contribute to a lot of early deaths⁵

2. Respiratory compromise

• Early life: Young children with chest restrictions often have fast breathing, blue skin, and many lung infections
• Chronic course: Survivors may develop chronic lung disease with reduced lung capacity and, therefore, experience tiredness when they move
• Interventions: Help given includes extra oxygen, body exercises, and in complex cases, chest opening surgeries (e.g, VEPTR—vertical expandable prosthetic titanium rib)

3. Cardiothoracic interactions

• About 60% of patients experience heart flaws (e.g hole between the upper heart chambers, merged or single upper heart chambers)³
• A thinner chest, along with heart oddities, ups the chance of illness, as both reduce the flow of oxygen and total heart-lung work

4. Radiographic features

• Chest X-rays show short ribs, tight spaces between ribs, and reduced chest space
• These signs are key to telling EVC apart from other bone growth issues

Differential diagnosis

A few other health issues have bone signs similar to EVC:

• Jeune asphyxiating thoracic dystrophy: A Tighter chest issue, often leads to death at a very young age
• McKusick-Kaufman syndrome: Shares the extra finger/toe trait but also comes with issues related to the genitalia
• Other ciliopathies: Short-rib extra finger/toe issues (types I–IV) often end in death around birth⁶

To tell them apart well, a mix of information from physical exams, X-ray views, and gene tests are required. 

Genetic and developmental basis

• EVC and EVC2 genes, set side-by-side on chromosome 4p16, make proteins found at the root of primary cilia
• Errors in these genes disrupt the Indian Hedgehog (IHH) and Sonic Hedgehog (SHH) paths, which are key for the growth of limb buds and ribs⁴
• This gives a reason for the mix of polydactyly, shortened limbs, and thoracic malformations

Knowing the genes helps in figuring out the disease, guessing what will happen, and talking to families about it, more so in families that are closely related or come from the same lineage.

Clinical implications

1. Early diagnosis

• Spotting postaxial polydactyly with short stature and thoracic restriction should lead to checks for EVC¹
• Prenatal ultrasound might show short long bones, polydactyly, and a narrow chest by the second trimester²

2. Prognosis

• Neonatal mortality: High, mostly from not being able to breathe well and heart-shaped issues⁵
• Long-term survival: Those who survive birth for a certain period of time often live long, but with some limits to what they can do

3. Management strategies

• Orthopedic care: Fixing extra fingers, heart-shaped issues, and helping with movement
• Respiratory support: Watching lung health and following steps to help with breathing
• Cardiac intervention: Quick heart surgery for wall defects when needed
• Multidisciplinary approach: Joining forces of bone doctors, lung doctors, heart doctors, gene experts, and mental support teams³

4. Quality of life considerations

• Being short and having visible bone issues can lead to psychological trauma and impact
• Talking it out early, having friends who support the individual, and physical therapy to help fit in are very beneficial

Future directions

• Genetic therapies: Better grasp of Hedgehog paths makes room for targeted treatments
• Surgical innovations: Advances in treatment to expand chest capacity could positively impact newborns’ lives
• Longitudinal studies: Further testing is needed to check understanding of adult breathing, facial bone issues, and quality-of-life challenges

Summary

In Ellis-Van Creveld syndrome, characteristic features of the arm and chest are key to what we see in this health issue. Mainly, arm faults may slow growth, harden moving, and shake up how well one lives. Yet, chest issues are the top risk to life as they can make it hard to breathe. We must spot these marks to name them early, weigh dangers, and plan care with a team to make the most informed decisions. As we learn more about genes and surgery gets better, results do too, but we still need to study this topic more to fully grasp the course of EVC and find the best ways to help those who are diagnosed with it.