61 Mesomelic Dwarfism, Langer Type
Mesomelic Dwarfism, Langer Type 759
Mesomelic dysplasia Langer type, Langer mesomelic dysplasia, mesomelic dwarfism of the hypoplastic ulna, fibula, and mandible type
Short-limb dwarfism, mesomelic micromelia, hypo- plasia of mandible
Frequency: Rare (fewer than 50 published cases).
Genetics
Autosomal recessive (OMIM 249700), due to ho- mozygous deletion or point mutation of SHOX gene mapped to Xpter-p22.32; this gene defect in the het- erozygous state causes Leri-Weill dyschondrosteosis
Clinical Features
• Short-limb dwarfism identifiable at birth
• Normal head and face
• Micrognathia
• Hypoplastic ulna, bowed radius
• Hypoplastic fibula, bowed tibia
• Short fingers, broad hands Differential Diagnosis
• Dyschondrosteosis, Leri-Weill type
• Other mesomelic disorders (Nievergelt syndrome, Reinhardt-Pfeiffer syndrome, and autosomal re- cessive Robinow syndrome)
Radiographic Features Limbs
• Mesomelic shortening and broadening of long bones
• Short and broad ulna,with severe hypoplasia of its distal end
• Marked angulation of the radius, with deformed radial head
• Absent distal ossification center of the ulna
• Severe hypoplasia of fibula (absence of proximal fibular ossification center)
• Marked shortening and widening of tibia, with metaphyseal flaring and medial angulation of dis- tal portion.
• Late appearance and early fusion of tibial epiphyses
• Varus deformity of humeral head
• Short femoral necks, large trochanters and femoral condyles
• Carpal abnormalities, decreased carpal angle
Spine
• Increased lumbar lordosis
Bibliography
Belin V, Cisin V, Viot G, Girlich D, Toutain A, Moncla A, Veke- mans M, Le Merrer M, Munnich A, Cormier-Daire V. SHOX mutations in dyschondrosteosis (Leri-Weill syndrome).
Nat Genet 1998; 19: 67–9
Canepa G, Maroteaux P, Pietrogrande V. Sindromi dismorfiche e malattie costituzionali dello scheletro. Piccin, Padova, 1996
Espiritu C, Chen H, Woolley PV. Mesomelic dwarfism as the homozygous expression of dyschondrosteosis. Am J Dis Child 1975; 129: 375–7
Fryns JP, van den Berghe H. Langer type of mesomelic dwarfism as the possible homozygous expression of dyschondrosteosis. Hum Genet 1979; 46: 21–7
Goldblatt J, Vallis C, Viljonen D, Beighton P. Heterozygous manifestations of Langer mesomelic dysplasia. Clin Genet 1987; 31: 19–24
Kunze J, Klemm T. Mesomelic dysplasia, type Langer – a ho- mozygous state for dyschondrosteosis. Eur J Pediatr 1980;
134: 269–72
Langer LO. Mesomelic dwarfism of the hypoplastic ulna, fibu- la, mandible type. Radiology 1967; 89: 654–60
M
Fig. 61.1. Patient 1, age 6 months. Micrognathia
Mesomelic Dwarfism, Langer Type 760
Fig. 61.2 a, b. Patient 1, age 6 months. Note marked shorten- ing of tibias and, to a greater extent, of fibulas. Tibias show wide shafts, medial bowing of distal shaft, metaphyseal flar- ing, and lack of proximal epiphyseal ossification. Fibulas are extremely short, with proximal deficiency and distally ossi- fied ends. Femurs are slightly short, with short and broad femoral necks. Pelvis is unaffected
a
b
Mesomelic Dwarfism, Langer Type 761
M
Fig. 61.3. a, b
Patient 1, age 6 months. Note se- vere shortening and broadening of ulna, with marked hypoplasia of the distal end; short and broad radius with lateral angulation of its distal end; and a grossly nor- mal hand. Humerus is mildly short and broad, with varus defor- mity of its head. c, d Patient 2, age 10 months. e Patient 2, at 27 years.
The deformities of the long bones are less pronounced than those seen in a and b, but similar.
(Reprinted, with permission, from Canepa et al. 1996)
a
c d e
b
