Apert Syndrome

Introduction

Syndrome characterized by
- bilateral complex syndactyly of hands and feet
  - index, middle, and ring fingers most affected
- symphalangism
- premature fusion of cranial sutures (craniosynostosis) results in flattened skull and broad forehead (acrocephaly)
- hypertelorism (increased distance between paired body parts, as in wide set eyes)
- normal to moderately disabled cognitive function
- glenoid hypoplasia
- radioulnar synostosis
Genetics
- autosomal dominant, but most new cases are sporadic
- mutation of FGFr2 gene
Epidemiology
- incidence is 1/80,000 live births
Prognosis
- spectrum of normal to moderately disabled cognitive function

Presentation

Physical exam
- dysmorphic face
  - craniosynostosis results in flattened skull and facial features
- rosebud hands (complex syndactyly where the index, middle, and ring finger share a common nail)

Imaging

Radiographs
- will show complex syndactyly

Treatment

Operative
- surgical release of border digits
  - indications
    - perform ~ 1 year of age
- digit reconstruction
  - indications
    - perform ~ 1.5 years of age
  - to convert central three digits into two digits

TAG

(OBQ10.247) A 4-year-old child has flattened facial features, wide set eyes, and the hand deformity pictured in Figure A. Which of the following is the most likely diagnosis? Topic

Review Topic

FIGURES: A

1. Apert's syndrome
2. Multiple epiphyseal dysplasia
3. Cleidocranial dysplasia
4. Noonan syndrome
5. Achondroplasia

PREFERRED RESPONSE ▶

DISCUSSION: Apert's syndrome is a congenital disorder causing deformity of the skull, face, hands, and feet. It affects 1/80,000 children. An autosomal dominant mode of inheritance exists, but the majority of new cases are sporadic. Early fusion of the cranial and facial suture lines (craniofacial synostosis) results in a variety of skull and facial deformities. The primary deformity of the hands and feet is severe syndactyly, often with fusion of the digits. The index, middle, and ring fingers are affected most often. Cognitive function may be normal or moderately disabled.

Rebelo et al reviews the hand deformities of 170 patients with Apert's syndrome and their clinical outcomes following surgical treatment.

Al-Qattan et al review the complex syndactyly of the hand associated with Apert's syndrome and suggests a new classification scheme.

Illustrations A-C are further examples of the face, hand, and foot deformities associated with Apert's syndrome

Illustrations: A

REFERENCES:

1. Rebelo N, Duarte R, Costa MJ, Leal MJ. Acrocephalosyndactyly -- the coalesced hand. Eur J Pediatr Surg. 2002 Feb;12(1):49-55. PMID:11967760 (Link to Abstract)

2. Al-Qattan MM, Al-Husain MA. Classification of hand anomalies in Apert’s syndrome. J Hand Surg Br. 1996 Apr;21(2):266-8. PMID:8732416 (Link to Abstract)

Question Authors:

John Badylak MD, Michael Hughes MD, Ben Taylor MD,

Please Rate Educational Value!

3.0

Average 3.0 of 6 Ratings

TAG

(OBQ07.142) Apert's syndrome is caused by a mutation in what gene? Topic

Review Topic

1. Fibroblast growth factor receptor 2 (FGFR2)
2. Fibroblast growth factor receptor 3 (FGFR3)
3. Collagen type II alpha 1 chain (COL2A1)
4. SED late (SEDL)
5. Fibrillin

PREFERRED RESPONSE ▶

DISCUSSION: Apert's syndrome (acrocephalosyndactyly type 1) is characterized by anomalies of the cranium, hands, and feet. Mutations in the FGFR2 gene cause Apert syndrome.

Anderson et al report that in Apert's syndrome there is widespread anomalies of the feet, with defects including both predictable dysmorphic changes and progressive fusions of the skeletal components during skeletal maturity.

Incorrect Answers:
2: Achondroplasia is related to abnormalities in the FGFR3, not FGFR2.
3: SED congenita is caused by mutations in COL2A1 (type II collagen alpha 1 chain) on chromosome 12. These result in abnormal type II collagen.
4:The X-linked form of SED tarda is caused by mutation in SEDL (SED late) gene.
5: Marfan syndrome is caused by defects in the fibrillin gene.

REFERENCES:

1. Anderson PJ, Hall CM, Evans RD, Hayward RD, Jones BM.. The feet in Apert’s syndrome. J Pediatr Orthop 1999; 19 504-507 PMID:10413001 (Link to Abstract)

Question Authors:

Greg Galano MD, Michael Hughes MD, John Badylak MD,

Please Rate Educational Value!

2.0

Average 2.0 of 16 Ratings

Level of Evidence 5 and Other Journal Articles (includes Case Reports, Expert Opinions, Personal Observations, and Biomechanic Studies)

Al-Qattan MM, Al-Husain MA. Classification of hand anomalies in Apert’s syndrome. J Hand Surg Br. 1996 Apr;21(2):266-8. PMID:8732416 (Link to Abstract)
Anderson PJ, Hall CM, Evans RD, Hayward RD, Jones BM.. The feet in Apert’s syndrome. J Pediatr Orthop 1999; 19 504-507 PMID:10413001 (Link to Abstract)
Rebelo N, Duarte R, Costa MJ, Leal MJ. Acrocephalosyndactyly -- the coalesced hand. Eur J Pediatr Surg. 2002 Feb;12(1):49-55. PMID:11967760 (Link to Abstract)

Textbooks

Review of Orthopaedics, 6th Edition, Mark D. Miller MD, Stephen R. Thompson MBBS MEd FRCSC, Jennifer Hart MPAS PA-C ATC, an imprint of Elsevier, Philadelphia, Copyright 2012
AAOS Comprehensive Orthopaedic Review, Jay R. Leiberman. Published by American Academy of Orthopaedic Surgeons, Rosemont IL. Copyright 2009
Orthopaedic Knowledge Update 10, John M Flyn. Published by American Academy of Orthopaedic Surgeons, Rosemont IL. Copyright 2011
Hoppenfeld SP. Surgical Exposures in Orthopaedics: The Anatomic Approach. Lipponcott, Williams, and Wilkins, Philadelphia, PA, Copyright 2009
Orthopaedic In-training Examination (OITE) Questions 2004-2012, American Academy of Orthopaedic Surgeons, Rosemont IL. Copyright 2004-2012
Self-Assessment Examination (SAE) Questions 2004-2012, American Academy of Orthopaedic Surgeons, Rosemont IL. Copyright 2004-2012

Qbank (3 Questions)

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