Cenani–Lenz syndactylism

Cenani–Lenz syndactylism
Synonyms	Syndactyly type 7
Pronounce
Field	Medical genetics, Orthopedics
Symptoms	Syndactyly, oligodactyly, synostoses, brachymesomelia, radius head dislocation
Complications	Reduced hand and foot function, limb deformities
Onset	Congenital
Duration	Lifelong
Types
Causes	Mutation in LRP4 gene
Risks	Autosomal recessive inheritance
Diagnosis	Clinical evaluation, genetic testing
Differential diagnosis	Other forms of syndactyly, hand and foot malformations
Prevention	Genetic counseling for carrier parents
Treatment	Surgical intervention for deformities
Medication
Prognosis	Varies based on severity, surgery can improve function
Frequency	Rare
Deaths	No specific mortality associated, depending on severity of complications

Cenani–Lenz syndactylism, also known as Cenani–Lenz syndrome or Cenani–syndactylism, is a rare genetic disorder primarily characterized by limb deformities affecting both the upper and lower extremities. This condition involves both syndactyly (fusion of fingers and/or toes) and oligodactyly (reduced number of fingers or toes), resulting in significant functional limitations.

Characteristics

Cenani–Lenz syndrome is marked by a variety of skeletal malformations, including:

• **Syndactyly**: Fusion of fingers and/or toes, often affecting both the hands and feet.
• **Oligodactyly**: A reduction in the number of digits in the hands and feet.
• **Carpal, metacarpal, and digital synostoses**: Abnormal fusion of bones in the hands and wrists, contributing to deformities and limited movement.
• **Disorganization of carpal bones**: Misalignment and fusion of wrist bones.
• **Radioulnar synostosis**: Fusion of the radius and ulna bones in the forearm, limiting rotation and movement.
• **Brachymesomelia**: Shortening of the upper limbs, particularly the forearms.
• **Metatarsal synostoses**: Fusion of bones in the feet.
• **Head dislocation of the radius**: A displacement of the head of the radius bone at the elbow joint.

These physical anomalies may result in varying degrees of disability, including challenges in motor function and daily activities. The severity of symptoms can differ from person to person.

Cause and Genetics

Cenani–Lenz syndactylism is inherited in an **autosomal recessive** pattern. This means that both parents must carry one copy of the defective gene for the child to inherit the condition. These carriers typically do not show symptoms, but they can pass the gene to their offspring.

The gene responsible for Cenani–Lenz syndrome is located on chromosome 13 and is associated with mutations in the LRP4 (Low-Density Lipoprotein Receptor-Related Protein 4) gene. Previous genetic studies, including tests involving the loci 15q13-q14, eliminated genes like FMN1 and GREM1 as candidates for causing the condition. LRP4 is crucial for bone development, and mutations in this gene impair limb formation during fetal development, leading to the characteristic skeletal abnormalities seen in the syndrome.

Diagnosis

Diagnosis of Cenani–Lenz syndactylism is based on clinical examination and may be confirmed with genetic testing. The clinical signs—such as syndactyly, oligodactyly, and other skeletal abnormalities—are usually apparent at birth, prompting medical evaluation. Genetic testing for mutations in the LRP4 gene can confirm the diagnosis.

Treatment

While there is no cure for Cenani–Lenz syndactylism, treatment typically involves addressing the physical deformities through **surgical interventions**. Surgery may be performed to separate fused fingers and toes (syndactyly), correct limb deformities, and address other skeletal abnormalities. In cases where the radius is dislocated, surgical correction may also be necessary to improve limb function.

Early intervention and surgery can greatly improve hand and foot function, and physical therapy may be recommended to support motor development and help patients achieve greater independence.

Prognosis

The prognosis for individuals with Cenani–Lenz syndactylism varies depending on the severity of the condition and the success of surgical interventions. With appropriate treatment, many individuals can achieve functional use of their hands and feet. However, lifelong management may be needed, particularly in cases with significant limb deformities or mobility challenges.

Eponym

The syndrome is named after two medical geneticists: Turkish geneticist Asim Cenani and German geneticist Widukind Lenz, who contributed to the identification and description of the condition.

See Also

• Syndactyly
• Oligodactyly
• LRP4
• Autosomal recessive disorders
• Congenital malformations
• Physical therapy for congenital disorders