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APERT'S SYNDROME

Introduction

Apert Syndrome is a rare but extremely severe acrosyndactlyly that affects cranial structures as well as fingers and toes during embryonic and fetal development. Mutations in the fibroblast growth factor receptor-2 (FGFR2) results in constant active signaling, which in turn, prohibits the normal interdigit differentiation process. This mutation is found in chromosome 10b.  The defect is inherited in autosomal fashion and the phenotype shows all digits joined together.  Despite the current understanding of the underlying genetic abnormalities, the clinical appearance of these children is usually sporadic.

Incidence and Associated Conditions

  • CA Birth Defects Monitoring Program reported incidence of 1 in 81,000 out of ~2.5M live births; Craniofacial Center at the North Texas Hospital for Children reported an incidence of 1 in 65,000 live births
  • Associated with Crouzon syndrome, Pfeiffer syndrome, Saethre-Chotzen syndrome, Mandibular prognathism

Associated Findings

  • Craniofacial: hyperacrobrachycephaly, craniofacial asymmetry, steep wide forehead, flat occiput, downslanting palpebral fissures, divergent upgaze, esotropic downgaze, depression of nasal bridge, ocular hypertelorism and proptosis, short and wide nose with bulbous tip and reduced anterior facial height
  • Oral: cleft palate, bifid uvula, impacted teeth, delayed or ectopic eruption, supernumerary teeth, thick gingiva, anterior and posterior open bite and cross bite
  • Skeletal: syndactyly of hands and feet, decreased glenohumeral mobility, radiohumeral synostosis, pectus excavatum, flattening of the chest wall, asymmetric chest wall, spina bifida, hemivertebrae, spinal fusions, scoliosis, lordosis, wide interpubic distance, genua valga and osseous ankylosis at the knees
  • Cutaneous: hyperhidrosis, oily skin, resistant acne, interrupted eyebrows, excessive forehead wrinkling, lateral plantar hyperkeratosis, skin dimpling over joints and oculocutaneous hypopigmentation
  • Neurological: megalencephaly, ventriculomegaly, corpus callosum anomalies, hippocampal hypoplasia or dysplasia, septum pellucidum hypoplasia or dysplasia, cerebral cortex dysplasia and anomalies of gyral patterning

Classification

  • Type I: "spade" hand; most common and least severe; thumb shows radial deviation and clinodactyly but is separated from the first finger; three middle fingers have normal length and are fused together; simple syndactyly in fourth web space
  • Type II: "spoon" or "mitten" hand; thumb is fused to first finger by simple complete or incomplete syndactyly; digits are fused at the distal interphalangeal joints, so a concave palm is formed
  • Type III: "hoof" or "rosebud" hand; most uncommon but most severe deformity; solid osseous or cartilaginous fusion of all digits; thumb is turned inward
ICD-10 Codes

  • APERT'S SYNDROME

    Diagnostic Guide Name

    APERT'S SYNDROME

    ICD 10 Diagnosis, Single Code, Left Code, Right Code and Bilateral Code

    DIAGNOSISSINGLE CODE ONLYLEFTRIGHTBILATERAL (If Available)
    APERT'S SYNDROMEQ87.0   

    Instructions (ICD 10 CM 2020, U.S. Version)

    USE ADDITIONAL CODE(S) TO IDENTIFY ALL ASSOCIATED MANIFESTATIONS

    ICD-10 Reference

    Reproduced from the International statistical classification of diseases and related health problems, 10th revision, Fifth edition, 2016. Geneva, World Health Organization, 2016 https://apps.who.int/iris/handle/10665/246208

Clinical Presentation Photos and Related Diagrams
  • Apert's Syndrome Left Hand palm
    Apert's Syndrome Left Hand palm
  • Apert's Syndrome Left Hand dorsum
    Apert's Syndrome Left Hand dorsum
  • Apert's Syndrome Left Hand ulnar view
    Apert's Syndrome Left Hand ulnar view
Symptoms
Webbed digits at birth, often all five digits of both hands.
Head and/or facial deformities
Webbed toes often on both feet.
Typical History

A typical patient is a baby or young child that presents with severe bilateral complex complete thumb to little finger syndactylys.  Patients have co-existing craniofacial deformities and complex toe syndactylys.  Decreased motion in the shoulders and elbows secondary to congenital deformities are also common.

Positive Tests, Exams or Signs
Work-up Options
Images (X-Ray, MRI, etc.)
  • X-ray of left long-ring simple syndactyly
    X-ray of left long-ring simple syndactyly
  • X-ray of right long-ring-liitle complex syndactyly
    X-ray of right long-ring-liitle complex syndactyly
  • X-ray of complex Apert's syndactyly
    X-ray of complex Apert's syndactyly
Treatment Options
Conservative

None available

Operative
  • General: finger release by zig-zag incisions, use of local skin flaps to reconstruct the commissure, use of skin grafts for additional skin
  • Type I: interdigital web space release; correction of thumb clynodactyly
  • Type II: release first and little fingers first, then middle and ring fingers; correction of thumb clinodactyly and lengthening (if needed)
  • Type III: release first and fourth web spaces to create a Type I hand; treat macerations and nailbed infections; lengthen thumb; amputation of first finger if necessary; release second and third interdigital web spaces last
  • Surgical release of border digits at ~1 year of age
  • Digit reconstruction by 2 years of age
Complications
  • Web recurrence
  • flexion contractures
  • infection
  • Short stiff fingers
  • Skin graft loss
Key Educational Points
  • Defects in the fibroblast growth factor receptor-2 (FCFR-2) pathway cause Apert's syndrome.
  • Surgical corrections should be done before age 2 if possible.
  • Skin flaps and grafts will be needed for Apert's construction.
  • There are three types of Apert's hand:
    • "spade hand"
    • "mitten hand"
    • "rosebud hand"
References

New Articles

  1. Vargel I, Calis M, Cavusoglu T, et al. Application of C-Shaped Osteotomy and Distraction Osteogenesis for Correction of Radial Angulation Deformities of the Hand in Children With Apert Syndrome: Review of 10 Years of Experience. Ann Plast Surg 2014 ePub. PMID: 25275478
  2. Fearon JA, Podner C. Apert syndrome: evaluation of a treatment algorithm. Plast Reconstr Surg 2013;131(1):132-42. PMID: 23271523

Reviews

  1. Liu C, et al. The molecular and cellular basis of Apert syndrome. Intractable Rare Dis Res 2013;2(4):115-22.  PMID: 25343114
  2. Oberg KC, et al. Developmental biology and classification of congenital anomalies of the hand and upper extremity. J Hand Surg Am 2010;35(12):2066-76 PMID: 21134615

Classics

  1. Blank CE. Apert's syndrome (a type of acrocephalosyndactyly)-observations on a British series of thirty-nine cases. Ann Hum Genet 1960;24:151-64. PMID: 13801313
  2. Hoover GH, Flatt AE, Weiss MW. The hand and Apert's syndrome. J Bone Joint Surg Am 1970;52(5):878-95. PMID: 5479478
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