What are the other Names for this Condition? (Also known as/Synonyms)

• Jeune Syndrome
• Short Rib Polydactyl Syndrome
• Thoracic-Pelvic-Phalangeal Dystrophy

What is Asphyxiating Thoracic Dystrophy? (Definition/Background Information)

• Asphyxiating Thoracic Dystrophy (ATD)  is a rare, inherited disorder characterized by abnormality in the development of bones, especially the bones of the chest, legs and arms, resulting in dwarfism and various other abnormalities
• The disorder may result in underdevelopment of the rib cage and unusually-shaped pelvic bones causing various thoracic/abdominal/pelvic abnormalities, including heart and lung defects, liver disease, and even kidney failure
• Asphyxiating Thoracic Dystrophy is a congenital condition that is manifested at childbirth. It is also called Jeune Syndrome. The condition is inherited in an autosomal recessive manner and a positive family history of ATD is a primary risk factor for the same
• A treatment of the disorder may require the involvement of healthcare providers across multiple specialties; mostly symptomatic treatment and surgery is considered. Nevertheless, in a majority of cases, the prognosis is unfavorable, and most children are known to die from complications arising from Asphyxiating Thoracic Dystrophy

Who gets Asphyxiating Thoracic Dystrophy? (Age and Sex Distribution)

• Asphyxiating Thoracic Dystrophy is present at birth, and may be noted during infancy or into early childhood
• Both males and females are affected
• ATD is a rare disorder with an estimated incidence at 1 per 100,000-130,000 live births
• There is no racial and ethnic predominance observed

What are the Risk Factors for Asphyxiating Thoracic Dystrophy? (Predisposing Factors)

• Currently, a positive family history of the disorder is the only known risk factor for Asphyxiating Thoracic Dystrophy
• No other specific risk factors are currently known

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others. 

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Asphyxiating Thoracic Dystrophy? (Etiology)

Asphyxiating Thoracic Dystrophy (ATD) is a genetic disorder that is inherited in an autosomal recessive pattern wherein two copies of an abnormal gene has been inherited on a non-sex chromosome.

• Alterations and changes that occur in the IFT80 gene are responsible in a majority of the families
• The IFT80 gene is responsible for producing a protein called cilia that is found in cell structures. The cilia plays an important role in:
  • Cell movement
  • Chemical signaling pathways
  • Sensory inputs
• Alterations that occur in an (as yet) undefined gene in chromosome 15 are also likely to cause Asphyxiating Thoracic Dystrophy

Autosomal recessive: Autosomal recessive conditions are traits or disorders that occur when two copies of an abnormal gene have been inherited on a non-sex chromosome. If both parents have an autosomal recessive condition, there is a 100% likelihood of passing on the mutated genes to their children. If, however, only one mutant copy of the gene is inherited, the individual will be a carrier of the condition, but will not be present with any symptoms. Children born to two carriers, have a 25% chance of being homozygous dominant (unaffected), a 50% chance of being heterozygous (carrier), and a 25% chance of being homozygous recessive (affected).

What are the Signs and Symptoms of Asphyxiating Thoracic Dystrophy?

The signs and symptoms observed in Asphyxiating Thoracic Dystrophy may vary from one individual to another and can be mild or severe. These may include:

• Dwarfism or short stature due to underdevelopment of the long bones of the arms and legs
• Failure to grow
• Polydactyly: Presence of extra fingers and toes in the hands and limbs
• Swelling of the ankle
• Dysplastic acetabula: abnormality in the formation of the cup-shaped cavity at the base of the hip bone into which the ball-shaped head of the femur fits
• Thoracic region abnormalities may include: The chest may be bell-shaped (narrow, elongated, and very short), which may lead to:
  • Short ribs
  • Breathing difficulties - rapid breathing or shortness of breath
  • Lung infections that are recurrent
  • High blood pressure
• Abdominopelvic region abnormalities causing:
  • Cystic renal disease: A genetic disorder characterized by the formation of numerous cysts in the kidneys
  • Cystic pancreatic disease: Sac-like packets of fluid found in the pancreas
  • Liver dysfunction
  • Pancreatic cysts
  • Improper growth of pelvic bones
  • Gastroenteritis
  • Recurring rectal prolapse
  • Diarrhea

How is Asphyxiating Thoracic Dystrophy Diagnosed?

The diagnostic procedures needed to confirm Asphyxiating Thoracic Dystrophy may include:

• A thorough physical examination for the presence of signs and symptoms that distinguishes Asphyxiating Thoracic Dystrophy is sufficient for the diagnosis of the disorder. These may include:
  • Breathing difficulties
  • Presence of narrow and small rib cage
  • Short limbs
• Urinalysis
• Pulmonary function testing will help in diagnosing restrictive lung disease
• Prenatal  diagnosis through ultrasound imaging

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Asphyxiating Thoracic Dystrophy?

Asphyxiating Thoracic Dystrophy may lead to the following complications namely:

• Failure to grow
• Pulmonary hypoplasia, which is the incomplete development of the lungs
• Herniation of the lung wherein a part of the lung is pushed through a tear in the chest wall, neck passageway, or diaphragm
• Renal failure due to cystic renal disease
• Hepatic cirrhosis: A chronic degenerative disease wherein the normal liver cells are damaged and are replaced by scar tissues
• Liver disease: Damages caused to the liver affecting the normal functioning of the liver
• Heart defects including congestive heart failure
• Subglottic stenosis, which is a narrowing of the airways resulting in breathing issues
• Dental abnormalities
• Retinal dystrophy: An eye disease that can lead to loss of eyesight
• Pneumothorax : A medical condition marked by the collection of air in the space around the lungs leading to collapsed lungs
• Mucous plugging of a bronchus: It is a medical condition wherein there is excess secretion of the slippery substance produced by the cells which lines the airways of the lungs
• Cardiac insufficiency: It is a medical condition in which the heart cannot pump enough blood throughout the body

How is Asphyxiating Thoracic Dystrophy Treated?

The treatment and management of Asphyxiating Thoracic Dystrophy may require the involvement of a variety of healthcare experts across diverse specialties. An individualized treatment plan may be required to address the medical issues. These may include:

• Symptomatic treatment is important
• Mechanical ventilation may be immediately provided to infants with respiratory distress
• Antibiotics, endotracheal suctioning, and postural drainage methods may be used in the treatment of respiratory infections
• Nasogastric and gastrostomy feedings may be necessary
• In severe cases, surgery may be recommended for chest reconstruction and enlargement of the thoracic cage through a process of median sternotomy
• Bone grafting and plate fixing may provide the time needed for normal thoracic cage growth
• Lateral thoracic expansion procedure may be done in children over 12 months’ old. This procedure includes:
  • The ribs are divided, and the underlying tissues arranged in a staggered fashion so that neither the rib nor periosteum covers the lung
  • New bone formation and the enlargement of the chest can be obtained through this arrangement
• Titanium ribs may be used in children with thoracic insufficiency syndrome
• Liver condition may be addressed symptomatically with focus on avoiding further liver damage
• Dialysis and renal transplantation are advised in case of renal failure
• Heart conditions may require appropriate surgical corrections

How can Asphyxiating Thoracic Dystrophy be Prevented?

Currently, there are no specific methods or guidelines to prevent Asphyxiating Thoracic Dystrophy since it is a genetic condition.

• Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
• If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders such as Hepatoerythropoietic Porphyria

Regular medical screening at periodic intervals with tests and physical examinations are highly recommended.

What is the Prognosis of Asphyxiating Thoracic Dystrophy? (Outcomes/Resolutions)

Most children with Asphyxiating Thoracic Dystrophy are known to survive only up to infancy or early childhood. The mortality rate is reportedly around 60-70%.

• Even with extensive medical and surgical intervention, the prognosis of children is extremely poor; many children succumb to the disorder during infancy
• Children who live longer are known to present a variety of complications from the liver, heart, and kidneys being affected; a small percentage are known to have chronic renal failures
• According to literature, only a few are known to overcome this disorder during the childhood stages to reach adolescence or adulthood

Additional and Relevant Useful Information for Asphyxiating Thoracic Dystrophy:

Asphyxiating Thoracic Dystrophy is known to resemble Ellis-Van Creveld syndrome, with the striking difference being that in Ellis-Van Creveld syndrome, the involvement of the thorax is less distinct, but the appearance of the pelvis is almost the same. According to some experts, it is difficult to differentiate between the two disorders.