Femoral Facial Syndrome - An Overview

What Is Femoral Facial Syndrome?

Femoral facial syndrome is also called femoral hypoplasia-unusual facies syndrome (FHUFS), bilateral femoral dysgenesis, and bilateral robin anomaly. This syndrome is a rare complex congenital anomaly that affects the femur bone, palate, and face. The first case of this syndrome was reported in 1975. The typical clinical presentation of this syndrome includes underdeveloped bowed thigh bone and unusual facial features. It causes dysmorphic facial features like upward-slanting eyes, shorter noses, broad nose tips, cleft palate, micrognathia (underdeveloped lower jaw), increased space between the nose and the upper lip, and thin upper lip. It also affects the genitourinary systems, heart, and lungs.

What Causes Femoral Facial Syndrome?

The precise cause of the condition remains unidentified. Most cases of femoral facial syndrome occur randomly without any reason. However, femoral facial syndrome is believed to occur due to genetic defects. Literature shows its association with a chromosomal abnormality in one of the cases of Femoral Facial Syndrome. This syndrome is also believed to be associated with maternal diabetes (a type of diabetes during pregnancy).

Femoral facial syndrome is inherited in an autosomal dominant pattern. Generally, for a genetic disease to occur, two copies of the altered gene are necessary to cause the disease. However, In a dominant genetic disorder, a single copy of the changed or mutated gene is sufficient to cause the disease. In humans, there are 23 pairs of chromosomes, with the initial 22 pairs known as non-sex chromosomes, while the final two pairs consist of sex chromosomes denoted as X and Y. Autosomal refer to the presence of harmful or altered genes in the non-sex chromosomes.

What Are the Clinical Presentations of Femoral Facial Syndrome?

Femoral facial syndrome (FFS) causes diverse clinical manifestations and usually starts to appear during pregnancy or in the stages of a newborn. The clinical manifestations of femoral facial syndrome are mentioned below.

• Femoral Hypoplasia: Abnormal underdevelopment or shortening of the thigh bone or absent femur.

• Cleft Palate: An abnormal opening along the roof of the mouth is one of the most commonly seen symptoms of FFS.

• Micrognathia: Underdeveloped lower jaw (mandible).

• Abnormalities of the Sacral Bone: Sacrum is one of the complex structures of the spine that is composed of five sacral vertebrae.

• Abnormalities of the Fibula: The fibula is one of the two long calf bones.

• Morphologic Abnormalities of the Hip Bone: Hip bones are the ring of bones that connect the backbone to the thighbone.

• Hypoplastic Tibia: Underdeveloped or absent of tibia (one of two long calf bones).

• Hip Dysplasia: Presence of congenital dysplasia (developmental abnormalities) of the hip.

• Long Philtrum: Philtrum refers to the groove between the nose and the upper lip. There is an increase in the distance between the nose and the upper lip.

• Melotia: Lowered position of the ears in the cheeks. The cartilage of the ear is present partially below the skin.

• Cleft Lip: Abnormal split or opening along the upper lip due to the improper closure of the lips during embryonic development.

• Short Nose: Decrease in length between the root of the nose to the nasal tip.

• Pre-axial Foot Polydactyl: Congenital malformation of the foot is characterized by a different segment consisting of the foot's first metatarsal or first cuneiform bone.

• Short Stature: Condition with restricted growth when the affected individual's height is lower than the ideal height of their age, gender, and population group.

• Thin Upper Vermillion: A condition in which the height of the vermilion border of the upper lip in the midline is more than two standard deviations below the average size.

• Talipes Equinovarus: This condition is called clubfoot, characterized by foot abnormalities.

• Upward slanting eyes.

• Abnormal Spinal Segmentation: A developmental abnormality that affects the separation of the vertebral column during development.

• Abnormalities of the kidney.

• Morphologic abnormalities of the ribcage.

• Long penis.

• Abnormal fusion of the radius and ulna bone (two forearm bones).

• Abnormal sideways curvature of the backbone.

• High elevated shoulder blade.

How Is Femoral Facial Syndrome Diagnosed?

A femoral facial syndrome is diagnosed by assessing the patient's clinical presentation. The doctor may evaluate the familial history of the patient. The clinician will determine the patient's facial features and thighs. With ultrasound, a diagnostic technique employing high-frequency sound waves to evaluate internal organs and structures, diagnosing this syndrome before birth is possible.

How Is Femoral Facial Syndrome Treated?

Femoral facial syndrome can occur due to genetic defects; hence, there is no cure. Supportive treatment is the only option of treatment in these patients. The patient may be referred to the concerned specialist to treat the symptoms.

• The affected child is referred to an orthopedic surgeon to treat bone deformities associated with FFS. The surgical interventions may include surgical lengthening of the bone or surgical repositioning of the femur head. The commonly performed surgical procedure includes femoralization of the tibia followed by hip orthoses.

• Treatment of FFS requires interprofessional collaboration to develop a treatment plan and rehabilitation program for these patients.

• The cleft palate may be treated by a maxillofacial surgeon to treat the patient operatively or by a dentist to provide the patient with an artificial device to close the opening with a prosthesis.

• The affected child may also be referred to a pediatrician, psychiatrist, speech therapist, physical therapist, and many other specialists based on the patient's symptoms.

• Since FFS is an autosomal dominant inheritance disorder, The patient with familial history of FFS is recommended for genetic counseling before planning for a pregnancy.

Conclusion:

A femoral facial syndrome is a rare congenital condition that affects the thigh bone, face, and various parts of the body. This syndrome is believed to be associated with diabetes in the mother during pregnancy and drug usage. And cases with autosomal dominant inheritance pattern is also reported. At present, there is no universally accepted treatment approach for this condition. The treatment of FFS requires an interdisciplinary approach that focuses on symptomatic and supportive care for the patient. Surgical intervention is carried out in these patients, depending on their age.