Introduction to Congenital Craniofacial and Musculoskeletal Abnormalities

Craniofacial and musculoskeletal abnormalities are common among children. They may involve only a single, specific site (eg, cleft lip, cleft palate, clubfoot) or be part of a syndrome of multiple congenital anomalies (eg, velocardiofacial syndrome, Treacher Collins syndrome). Careful clinical assessment may be necessary to distinguish an isolated abnormality from an atypical or mildly manifested syndrome.

Congenital abnormalities may be classified as

A deformity is an alteration in shape due to unusual pressure and/or positioning in utero (eg, some forms of club foot) or after birth (eg, positional plagiocephaly—head flattening due to prolonged lying in one position). Deformities are present in about 2% of births; some resolve spontaneously within a few days, but others persist and require treatment.

A malformation is an error in normal organ or tissue development. Causes include chromosomal abnormalities Overview of Chromosomal Anomalies Chromosomal anomalies cause various disorders. Anomalies that affect autosomes (the 22 paired chromosomes that are alike in males and females) are more common than those that affect sex chromosomes... read more , single-gene defects Single-Gene Defects Genetic disorders determined by a single gene (Mendelian disorders) are easiest to analyze and the most well understood. If expression of a trait requires only one copy of a gene (one allele)... read more , teratogenic agents Exposure to Teratogens Risk factors for complications during pregnancy include Preexisting maternal disorders Physical and social characteristics (eg, age) Problems in previous pregnancies (eg, a previous history... read more , or a combination of genetic and environmental factors; a decreasing number of cases are considered idiopathic. Congenital malformations are present in about 3 to 5% of births. A clinical geneticist should assess affected patients to establish a definitive diagnosis, which is essential for formulating an optimal treatment plan, providing anticipatory guidance and genetic counseling, and identifying relatives at risk of similar abnormalities.

Arthrogryposis multiplex congenita Arthrogryposis Multiplex Congenita Arthrogryposis multiplex congenita refers to a group of rare congenital disorders characterized by multiple joint contractures present at birth. These disorders result from limitation of joint... read more (AMC) refers to a group of rare congenital disorders characterized by multiple joint contractures present at birth. These disorders result from congenital limitation of joint movement in utero. Many pathologic processes that cause immobilization of a fetus' limbs during or shortly after the embryonic formation of joints may result in AMC. AMC occurs when embryofetal neuromuscular function and development are impaired.

Congenital craniofacial abnormalities Overview of Congenital Craniofacial Abnormalities Congenital craniofacial abnormalities are a group of defects caused by abnormal growth and/or development of the head and facial soft-tissue structures and/or bones. (See also Introduction to... read more are caused by the abnormal growth and/or development of the head and facial soft-tissue structures and/or bones. The most common abnormalities of the face are cleft lip and cleft palate Cleft Lip and Cleft Palate An oral-facial cleft is a birth defect in which the lip, the roof of the mouth, or both do not close in the midline and remain open, creating a cleft lip and/or cleft palate. These defects are... read more . Other abnormalities may involve the ears Congenital Ear Abnormalities Ears can be absent, deformed, or incompletely developed at birth. (See also Introduction to Congenital Craniofacial and Musculoskeletal Disorders and Overview of Congenital Craniofacial Abnormalities... read more , eyes Congenital Eye Abnormalities Eyes can be absent, deformed, or incompletely developed at birth, often in conjunction with other congenital abnormalities and syndromes. (See also Introduction to Congenital Craniofacial and... read more , and jaw Congenital Jaw Abnormalities The jaw can be missing, deformed, or incompletely developed at birth, often in conjunction with other congenital abnormalities and syndromes. (See also Introduction to Congenital Craniofacial... read more . Some of the craniofacial abnormalities that affect the skull include macrocephaly Macrocephaly Macrocephaly (megacephaly) is a head circumference > 2 standard deviations above the mean for age ( 1, 2). (See also Introduction to Congenital Craniofacial and Musculoskeletal Disorders and... read more , microcephaly Microcephaly Microcephaly is a head circumference < 2 standard deviations below the mean for age. (See also Introduction to Congenital Craniofacial and Musculoskeletal Disorders and Overview of Congenital... read more , cranium bifidum or related ossification defects, and craniosynostosis Craniosynostosis Craniosynostosis is premature fusion of one or more calvarial sutures. (See also Introduction to Congenital Craniofacial and Musculoskeletal Disorders and Overview of Congenital Craniofacial... read more .

Congenital hip and joint abnormalities include developmental dysplasia of the hip Developmental Dysplasia of the Hip (DDH) Developmental dysplasia of the hip (formerly congenital dislocation of the hip) is abnormal development of the hip joint. (See also Introduction to Congenital Craniofacial and Musculoskeletal... read more and knee dislocation Congenital Knee Dislocation The knee may be dislocated at birth. (See also Introduction to Congenital Craniofacial and Musculoskeletal Disorders.) Anterior knee dislocation with hyperextension is rare at birth but requires... read more .

Congenital limb defects Congenital Limb Abnormalities Congenital limb defects involve missing, incomplete, supernumerary, or abnormally developed limbs present at birth. (See also Introduction to Congenital Craniofacial and Musculoskeletal Disorders... read more are numerous. Sometimes a limb is missing or incomplete. Part or all of the hand or foot may be missing. For example, the person may have polydactyly Polydactyly Congenital limb defects involve missing, incomplete, supernumerary, or abnormally developed limbs present at birth. (See also Introduction to Congenital Craniofacial and Musculoskeletal Disorders... read more or syndactyly Syndactyly Congenital limb defects involve missing, incomplete, supernumerary, or abnormally developed limbs present at birth. (See also Introduction to Congenital Craniofacial and Musculoskeletal Disorders... read more . Talipes equinovarus Talipes Equinovarus (Clubfoot) and Other Foot Abnormalities Talipes equinovarus, sometimes called clubfoot, is characterized by plantar flexion, inward tilting of the heel (from the midline of the leg), and adduction of the forefoot (medial deviation... read more (clubfoot) is a defect in which the foot and ankle are twisted out of shape or position. Other foot defects include metatarsus adductus Metatarsus adductus Talipes equinovarus, sometimes called clubfoot, is characterized by plantar flexion, inward tilting of the heel (from the midline of the leg), and adduction of the forefoot (medial deviation... read more , metatarsus varus Metatarsus varus Talipes equinovarus, sometimes called clubfoot, is characterized by plantar flexion, inward tilting of the heel (from the midline of the leg), and adduction of the forefoot (medial deviation... read more , talipes calcaneovalgus Talipes calcaneovalgus Talipes equinovarus, sometimes called clubfoot, is characterized by plantar flexion, inward tilting of the heel (from the midline of the leg), and adduction of the forefoot (medial deviation... read more , and pes planus Pes planus (flat feet) Talipes equinovarus, sometimes called clubfoot, is characterized by plantar flexion, inward tilting of the heel (from the midline of the leg), and adduction of the forefoot (medial deviation... read more .

In genu varum Genu Varum (Bowlegs) and Genu Valgum (Knock-Knees) The 2 major types of knee or femoral-tibial angular deformities are genu varum (bowlegs) and genu valgum (knock-knees). Untreated, both can cause osteoarthritis of the knee in adulthood. (See... read more (bowlegs), the knees appear to be turned outward. In genu valgum Genu Varum (Bowlegs) and Genu Valgum (Knock-Knees) The 2 major types of knee or femoral-tibial angular deformities are genu varum (bowlegs) and genu valgum (knock-knees). Untreated, both can cause osteoarthritis of the knee in adulthood. (See... read more (knock-knees), the knees appear to be turned inward. Other defects that affect the legs include femoral torsion Femoral Torsion (Twisting) The femoral head may be twisted at birth. (See also Introduction to Congenital Craniofacial and Musculoskeletal Disorders.) Femoral torsion is common among neonates and may be either Internal... read more and tibial torsion Tibial Torsion The tibia may be twisted at birth. Tibial torsion can be external (lateral) or internal (medial). (See also Introduction to Congenital Craniofacial and Musculoskeletal Disorders.) External tibial... read more .

Muscle abnormalities Congenital Muscle Abnormalities Individual muscles or groups of muscles may be absent or incompletely developed at birth. (See also Introduction to Congenital Craniofacial and Musculoskeletal Disorders.) Muscle abnormalities... read more may be congenital. Infants can be born missing individual muscles or groups of muscles, or muscles can be incompletely developed. Muscle abnormalities can occur alone or as part of a syndrome.

Congenital neck and back abnormalities Congenital Neck and Back Abnormalities Neck and back abnormalities can be caused by soft-tissue or bony injuries or by vertebral anomalies. (See also Introduction to Congenital Craniofacial and Musculoskeletal Disorders.) Vertebral... read more can be caused by injuries to soft tissues or bones. Two of the most common abnormalities are

Spinal abnormalities include scoliosis Idiopathic Scoliosis Idiopathic scoliosis is lateral curvature of the spine. Diagnosis is clinical and includes spinal x-rays. Treatment depends on the severity of the curvature. Idiopathic scoliosis is the most... read more , which is rarely apparent at birth, and defects of a specific vertebra, which are likely to be identified at birth. A number of different genetic syndromes include scoliosis as one of their abnormalities. As children grow, the curve can progress quickly. Moderate curves (20 to 40°) are treated conservatively (eg, physical therapy and bracing) to prevent further deformity. Severe curves (> 40°) may be ameliorated surgically (eg, spinal fusion with rod placement).

Patients with apparent congenital anomalies should be referred for clinical genetic evaluation. Chromosomal microarray Diagnosis Chromosomal anomalies cause various disorders. Anomalies that affect autosomes (the 22 paired chromosomes that are alike in males and females) are more common than those that affect sex chromosomes... read more , specific gene tests, or broader gene panel tests should be considered in the evaluation of patients with congenital craniofacial and musculoskeletal abnormalities. If the results of these tests are nondiagnostic, whole exome sequencing analysis is recommended.