summary Diastrophic Dysplasia is a rare congenital disorder caused by an autosomal recessive mutation in the DTDST gene leading to a defect in the sulfate transporter protein. Patients present with a form of short-limbed dwarfism with characteristic features such as cauliflower ears, hitchhiker thumbs, and severe cervical kyphosis. Diagnosis is made based on family history associated with typical radiographic and clinical features. No commercially available diagnostic test exists due to the variety of genetic mutations. Treatment involves a multidisciplinary approach to improve and maintain function. Surgical spinal instrumentation and fusion are indicated in patients with atlantoaxial instability, cervical myelopathy, or progressive scoliosis. Epidemiology Demographics more common in Finland rare in rest of world Etiology Genetics autosomal recessive mutation in DTDST gene (SLC26A2) on chromosome 5 encodes for sulfate transporter protein mutation is present in 1 in 70 Finnish citizens leads to undersulfation of cartilage proteoglycan Presentation Physical exam and syndrome features short stature ("twisted dwarf") rhizomelic shortening cleft palate (60%) cauliflower ears (80%) poorly developed UE hitchhikers thumb thoracolumbar scoliosis severe cervical kyphosis hip and knee contractures genu valgum skewfoot (serpentine or Z foot) tarsometatarsal adductus and valgus hindfoot rigid clubfeet (equinocavovarus) Imaging Radiographs recommended views AP and lateral of cervical spine and thoracolumbar spine three joint standing lower extremity films to assess alignment Ultrasound can be used to make diagnosis prenatally Treatment Nonoperative observation and supportive treatment indications most patients modalities cauliflower ears frequently repsond to early treatment with compressive bandages cervical kyphosis frequently resolves spontaneously Operative occipital-cervical fusion indications atlantoaxial instability with neurologic symptoms risk of quadriplegia is a concern posterior cervical fusion indications cervical kyphosis that does not resolve spontaneously thoracolumbar fusion indications kyphoscoliosis of thoracolumbar spine if progressive may require ASF / PSF soft tissue surgical release indications early foot ankle deformity after initial period of casting severe joint contractures (hip and knee) osteotomies for correction indications progressive valgus deformity of lower extremities (with dislocated patellae) resistant or recurrent clubfeet distal femoral extension osteotomies for fixed knee flexion contractures valgus intertrochanteric osteotomies +/- acetabuloplasty for early hip subluxation total joint arthroplasty indications end stage osteoarthritis of hips
QUESTIONS 1 of 4 1 2 3 4 Previous Next (OBQ12.8) A child with a defect in the DTDST gene would have which of the following classic phenotypes? QID: 4368 Type & Select Correct Answer 1 Blue sclera and bowing deformities 7% (339/5029) 2 Mental retardation and cardiac malformations 6% (283/5029) 3 Cauliflower ears and hitchhiker's thumb 64% (3198/5029) 4 Craniosynostosis and complex syndactyly 13% (633/5029) 5 Rhizomelic dwarfism and frontal bossing 9% (475/5029) L 3 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review Tested Concept Review Full Topic (OBQ09.49) What is the genetic cause of the dwarfism characterized by a hitchhikers thumb, cauliflower swelling of the ears, and severe clubfeet? QID: 2862 Type & Select Correct Answer 1 FGFr-2 8% (323/4017) 2 FGFr-3 12% (468/4017) 3 Sulfate transport protein 68% (2746/4017) 4 CBFA-1 7% (297/4017) 5 Gs Alpha Protein 4% (164/4017) L 2 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 3 Review Tested Concept Review Full Topic (OBQ05.29) Figure A is a photograph of a newborn's hand. Genetic testing reveals a mutation in the SLC26A2 gene on Chromosome 5q and both the parents were carriers. What condition does this child have? QID: 66 FIGURES: A Type & Select Correct Answer 1 Achondroplasia 6% (115/2027) 2 Osteogenesis imperfecta 1% (12/2027) 3 Hypochondroplasia 7% (152/2027) 4 Diastrophic dysplasia 81% (1649/2027) 5 Ehlers-danlos syndrome 5% (93/2027) L 1 Question Complexity D Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 4 Review Tested Concept Review Full Topic (OBQ04.104) A 3-year-old child with short-limbed dwarfism has the clinical features shown in Figures A & B. What is the pathoanatomy of this disease? QID: 1209 FIGURES: A B Type & Select Correct Answer 1 Sulfate transport protein gene mutation affecting cartilage matrix formation 66% (960/1449) 2 Mutation in the gene CBFA-1 affecting osteocalcin formation 6% (94/1449) 3 Defect in lysosomal-storage 5% (74/1449) 4 Defect in lipid-storage 2% (24/1449) 5 Mutation in gene FGFR-3 resulting in growth plate growth abnormality 20% (290/1449) L 2 Question Complexity B Question Importance Select Answer to see Preferred Response SUBMIT RESPONSE 1 Review Tested Concept Review Full Topic
All Videos (1) Podcasts (1) Login to View Community Videos Login to View Community Videos 12th International Congress on Early Onset Scoliosis - 2018 Diastrophic Dysplasia - Vernon Tolo, MD (ICEOS 2018, #58) Vernon Tolo Pediatrics - Diastrophic Dysplasia A 2/12/2019 283 views 4.5 (2) Pediatrics⎪Diastrophic Dysplasia Orthobullets Team Pediatrics - Diastrophic Dysplasia Listen Now 12:22 min 4/28/2020 205 plays 0.0 (0)