Pierquin Syndrome - Clinical Features, Causes, and Management

Introduction

In 1989 Dr.Pierquin reported two sibling fetuses with a combination of postaxial polydactyly and dandy walker malformation. Later in 2013, another group of doctors reported an infant with the same features and other cardiac and ophthalmologic manifestations described by Dr.Pierquin. They decided to call this condition Pierquin syndrome. The main characteristic feature of Pierquin syndrome is the association of dandy-walker malformation with postaxial polydactyly.

What Is Pierquin Syndrome?

Pierquin syndrome is also known as dandy-walker malformation-postaxial polydactyly syndrome. It is a rare syndromic disorder, and the main feature of this syndrome includes a neurological disorder called dandy-walker malformation and polydactyly in the hands and feet. Pierquin syndrome also affects many other body systems.

How Is Pierquin Syndrome Caused?

• Pierquin syndrome is a genetic disorder and is caused due to alterations in the genetic material (DNA) of an individual.

• The exact cause of Pierquin syndrome is not currently known. Perquin syndrome is suspected to be caused due to mutations in multiple genes.

• Pierquin syndrome has an autosomal recessive inheritance pattern, which means that the affected individual received a pathological variant gene from both parents (that is, the affected person has two copies of the mutated gene). Each parent of the affected individual is a carrier having one copy of the pathologically variant gene and usually no symptoms.

What Are the Clinical Features of Pierquin Syndrome?

Symptoms of Pierquin syndrome start appearing during pregnancy and as a newborn. The severity and the number of symptoms differ among different affected persons.

Main Clinical Features

• Dandy-Walker Malformation - It is a congenital brain malformation. It is characterized by enlargement of the posterior fossa of the brain, incomplete formation of the cerebellar vermis, and dilation of the fourth ventricle. In other words, dandy-walker malformation can be described as a cerebellum cyst involving the fourth ventricle.

• Hydrocephalus - The dandy-walker cysts may interfere with draining cerebrospinal fluid from the brain, resulting in fluid accumulation and hydrocephalus.

• Postaxial Polydactyly - This refers to extra digits on the ulnar side (side of the fifth finger) of the hands. Polydactyly may also be present in the feet. Other features associated with polydactyly include enlargement of the fifth metatarsal and metacarpal bones and bifid metacarpals.

Other Symptoms

• Abnormalities of the Head and Neck

  • Depressed and wide nasal bridge.

  • Low-set ears.

  • Eye abnormalities like chorioretinal atrophy, nystagmus (rhythmic involuntary oscillations of the eyes), and posterior embryotoxic.

  • Narrow palpebral fissure.

• Abnormalities of the Cardiovascular System

  • Vascular dilatation.

  • Aortic valve stenosis (narrowing of the aortic valve).

  • Patent ductus arteriosus.

• Abnormalities Associated With Dandy-Walker Malformation, Nervous, and Musculoskeletal System.

  • Dolichocephaly.

  • Macrocephaly.

  • Microretrognathia (developmental defect of mandible).

  • The posterior fossa bone becomes thin and bulged out.

  • Frontal bossing (bulging of lateral frontal bone prominences).

  • Cranial nerve paralysis ( injury to cranial nerves which causes muscle weakness).

  • Absence of a part of the cerebellar vermis.

  • Truncal ataxia.

  • Dilated fourth ventricle.

  • Joubert syndrome is characterized by hypotonia, cerebellar and brain stem malformation, and developmental delays.

  • Intellectual disability.

  • Motor coordination difficulties.

  • Fleshy tumors of the tongue in rare cases.

How Is Pierquin Syndrome Diagnosed?

The diagnosis of Pierquin syndrome is usually made through a combination of physical examination, imaging studies, and genetic testing.

• Physical Examination - A physical examination will reveal the presence of polydactyly and other characteristic physical features.

• Neurological Examination - A neurological examination may reveal signs of dandy-walker malformation such as hydrocephalus, cerebellar hypoplasia, and other brain structural abnormalities.

• Imaging Studies - Imaging studies such as MRIs and CT scans can help visualize the structural abnormalities of the brain associated with dandy-walker malformation. Imaging studies may also help detect the severity and the presence of hydrocephalus and other associated complications. X-rays may help confirm the presence and severity of polydactyly.

• Genetic Testing - Genetic testing may be recommended to determine the underlying genetic abnormalities that cause the syndrome. This involves testing for specific genetic mutations associated with this condition or performing chromosomal analysis to detect any chromosomal abnormalities.

• Prenatal Diagnosis - Prenatal testing can be performed for couples with a family history of the syndrome or couples with a child with the syndrome. In some cases, Pierquin syndrome may be detected during prenatal screening or diagnostic tests such as ultrasound or amniocentesis.

How Is Pierquin Syndrome Managed?

The treatment for Pierquin syndrome depends on the severity of the condition and associated symptoms. The treatment for this syndrome varies according to the patient's individualized needs and may require a team of specialists. Treatment aims to manage symptoms, prevent complications, and improve quality of life. Some of the treatment options include.

• Medical Management: Pressure in the skull due to hydrocephalus may cause symptoms like headaches, nausea, seizures, and vomiting. Drugs can be prescribed to alleviate these symptoms. Certain medications may be prescribed to manage associated symptoms such as seizures or hydrocephalus (excess fluid in the brain).

• Shunting: If there is too much cerebrospinal fluid in the brain, a surgery called shunting may be done to drain it. A shunt is a small tube that helps drain extra fluid in the brain and sends it to another part of the body, typically the abdomen, where it can be absorbed.

• Surgical Interventions: Surgery may sometimes be required to remove the extra digits and correct any associated symptoms. Surgical intervention may also be required to correct the complications from dandy-walker malformation.

• Physical Therapy and Rehabilitation: For individuals with motor coordination and balance difficulties, physical therapy can be beneficial in improving their functional abilities.

• Other Supportive Therapies: Various supportive therapies like occupational therapy, and speech therapy can be done to improve motor function, coordination, and speech development.

• Genetic Counseling: Individuals with Pierquin syndrome and their families may benefit from genetic counseling to better understand the underlying genetic abnormalities and the chances of passing the condition to their offspring.

It is important to understand that the way each person is treated may be different, and decisions about treatment are made together with a group of healthcare professionals, such as neurologists, neurosurgeons, and other specialists, to provide complete care.

Conclusion

Pierquin syndrome is a rare genetic condition. People affected by this syndrome and their families should be educated about the condition and supported with support groups and counseling. Appropriate treatment for the symptoms can improve the quality of life of the affected individual.