Overview

Achondrogenesis is a group of rare genetic disorders that results in skeletal dysplasia characterised by developmental cartilage and bone defects.¹ This disorder is lethal and affects 1 in 40,000 live births. Affected individuals are commonly stillborn, or die shortly after birth. 

Achondrogenesis type IA and IB result from autosomal recessive genetic mutations in the TRIP11 and SLC26A2 genes, respectively, whereas type II is caused by de novo (present for the first time) autosomal dominant mutations in the COL2A1 gene.² Although the different types of achondrogenesis share similar clinical symptoms, such as severely reduced bone length and shortened ribs, they can typically be prenatally distinguished by a combination of clinical, radiologic, and histologic features.¹ 

Diagnosis and management of achondrogenesis

Initial diagnosis is made through an ultrasound examination, a non-invasive procedure generally scheduled routinely during pregnancy that introduces minimal radiation to the foetus.^2,3,4,5 Foetal magnetic resonance imaging (MRI) and/or low-dose foetal computed tomography (CT) may be performed following thorough counselling on the respective benefits and risks if ultrasound results are not confirmatory.⁶ Alternatively, either non-invasive methods such as cell-free foetal DNA in maternal blood or invasive methods such as amniocentesis can be used to obtain foetal DNA for genetic testing to identify disease-causing mutations.^2,7 

In cases where prenatal diagnosis was uncertain, postnatal diagnosis may be carried out through genetic testing or physical examination to assess recurrence risk and guide future pregnancies. 

Individuals with achondrogenesis are unable to survive due to respiratory problems that arise from a lack of skeletal support for the lungs.⁶ Advancements in the medical field have led to potential postnatal treatment options to address this issue, such as inserting a titanium rod to expand the chest. This intervention would facilitate spine and lung growth, thereby improving respiration.

Importance of ethical considerations 

The complexity of the uncertainties and risks associated with prenatal diagnostic methods and results, along with the emotional burden on families, necessitates a careful and ethically sound approach in the management of achondrogenesis. Addressing relevant ethical considerations is paramount in ensuring that medical decisions are made in the best interest of affected individuals and their families.

Accuracy and reliability of prenatal diagnosis

Prenatal screening is a morally sensitive practice as it could result in, or influence, decisions to terminate a pregnancy in the case of positive results. Parents often have a strong desire for healthy children, which supports the argument that terminating a pregnancy due to a lethal disorder can be justifiable. The grey area in the debate regarding achondrogenesis is the issue of accuracy and reliability in prenatal diagnosis.

Statistics indicate that prenatal ultrasound can approach a 100% accuracy rate for diagnosing lethal skeletal dysplasias, including achondrogenesis, when clear diagnostic criteria are applied.⁵ Additional diagnostic procedures, such as a CT scan or genetic testing, may also be performed to confirm or rule out a diagnosis. However, not all mutations in the disease-associated genes result in achondrogenesis, and different disease-causing mutations can lead to varying degrees of severity.^3,4 Misinterpreted test results may lead parents to make decisions they might not have made with accurate information, such as terminating a pregnancy.⁸

Given the uncertainty in diagnostics, it is imperative that healthcare providers are thoroughly trained in communicating the uncertainties and risks associated with prenatal diagnosis to parents. Further research into the disorder and its genetic variants is also important for improving risk assessment and management advice in the future. 

Counselling and informed consent

Adequate counselling and support for parents are essential for informed decision-making in the management of achondrogenesis.^8,9 This includes providing information about the advantages and limitations of various technologies, as well as the care pathways available after results are obtained.

The costs and risks associated with recommended management measures, as well as possible alternatives, should be disclosed. For example:

• The risk of miscarriage with amniocentesis and the potential for inducing childhood cancer with CT scans^2,6,9
• The turnaround time for test results may not allow sufficient time for pregnancy management²
• The risk that the conceived child will have developmental defects or other health complications if the pregnancy is continued in the case of suspected achondrogenesis
• The financial costs of palliative care or available treatments for a conceived child with birth defects

Counselling should be obligatory when an achondrogenesis diagnosis is suspected. Moreover, emotional and psychological support services should be easily accessible if parents need assistance in easing stress and anxiety. This is critical in minimising the influence of financial and emotional burdens and information gaps on decision-making and ensures that parents make voluntary and informed decisions throughout the management of achondrogenesis. 

Following appropriate counselling, parents should be well-equipped with knowledge for future planning, including appropriate delivery methods, pregnancy planning, postnatal care options, and available medical interventions. 

Parental choices and autonomy

The expectation that assigned female at birth (AFAB), or parents, will make autonomous decisions about pregnancies may feel like a heavy burden. They may often be vulnerable to social pressures, family demands, and healthcare provider expectations. For instance, if society expects AFAB to produce only healthy children, relying on their “autonomy”, it risks treating them as mere means to fullfil social demands.¹⁰ This would place the responsibility of making these difficult decisions solely on pregnant AFAB, or parents, who may be undergoing significant emotional and psychological stress. Therefore, society must respect and support parents' free decision-making and work towards improving decision-making conditions in the case of achondrogenesis management.

Prenatal genetic testing and eugenics

Prenatal genetic testing is a contentious issue influenced by technological advancements and evolving ethical debates. The complexity and uncertainty of achondrogenesis genetic variants and their clinical severity require careful consideration when assessing grounds for pregnancy termination. There is a risk that, for less severe health complications, pregnancy termination could be misused as a rationale for diminishing societal support and inclusivity for people with disabilities.^9,10 

It is crucial to prevent such practices from veering into eugenics and to ensure that we improve inclusion and support for people with disabilities. This approach helps to avoid creating moral pressure to terminate pregnancies due to perceived insufficient support and inclusivity for individuals with disabilities.

Summary

Achondrogenesis is a group of rare and lethal skeletal dysplasias caused by genetic mutations. Diagnosis typically occurs prenatally through methods such as ultrasound, CT scans, and genetic testing. Policymakers and healthcare providers play a crucial role in ensuring safe and ethical management of achondrogenesis, especially in response to technological advancements. This involves addressing uncertainties about the accuracy and reliability of diagnostic results, offering appropriate counselling and support services to help parents make informed decisions, and establishing legal guidelines to prevent unethical practices such as "selective breeding." Additionally, the general public should support individuals facing difficult decisions related to achondrogenesis diagnoses and work towards fostering a more inclusive environment for people with disabilities.