Spondylothoracic dysplasia type I (Jarcho-Levin syndrome) . It is characterized by multiple vertebral and rib malformations that leads to the trunk and neck shortening. The posterior convergence of the ribs and their anterior flaring lead to the characteristic crab chest deformity. Respiratory insufficiency due to the consequent pulmonary hypoplasia is the most common cause of death . This type has an autosomal recessive inheritance.
Spondylocostal dysplasia (spondylothoracic dysplasia type II) - less severe form. The ribs abnormalities are dominant and include hypoplasia, fusion and reduction of their number. The skull and limbs are normal, but there is a higher incidence of congenital heart and urinary anomalies . This type has an autosomal dominant inheritance.
According to Wong, spondylocostal dysplasia and spondylothoracic dysplasia are two different subtypes of Jarcho-Levin syndrome, but there is considerable overlap between them in the literature [2, 3]. The type of vertebral anomalies are not helpful in differentiating between the two types .
Spondylothoracic dysplasia was first described by Jarcho-Levin in 1938. More than 140 cases have been described in the literature, but predominantly the type I. The first prenatal ultrasonographic diagnosis of Jarcho-Levin syndrome was done in 1987 and again in 1989, when the sonographic criteria for this condition were described . Initially the prenatal diagnosis of Jarcho-Levin syndrome was postulated in the second trimester and later even in the first trimester . The most of the reports have described the prenatal sonographic diagnosis in families known to be at risk. Description of the spondylothoracic dysplasia type II is exceptional.
Both types are rare anomalies. The ratio of reported spondylocostal dysplasia to spondylothoracic dysplasia is 1:6.
Unknown. Furthermore, banding studies of the chromosomes, biochemical essays and genetic probes are not available for confirming the diagnosis . In both of these subtypes, the karyotype is typically normal.
Spondylocostal dysplasia is autosomal dominant disorder with a defect in vertebral segmentation during early embryogenesis (weeks 4-6) and secondary anomalies of the trunk and thorax .
Both of these two subtypes have an abnormal spine with defects of segmentation including absent vertebrae, hemivertebrae and fused vertebrae. The rib abnormalities can help to distinguish the two subtypes:
The "crab chest" deformity of spondylothoracic dysplasia is due to the fusion of the posterior elements of the ribs with flaring of the anterior ends.
In spondylocostal dysplasia (spondylothoracic dysplasia type II) the ribs have intrinsic abnormalities of fusion and bifurcation, but don"t have a flared out appearance. The thorax deformities are less severe. Spondylocostal dysplasia is often associated with multiple extravertebral anomalies. Concerning SCD, antenatal diagnosis is exceptional.
In our case the first trimester sonography showed to be too early for recognizing of vertebral or thoracic malformations.
Implications for targeted examinations
3D ultrasound can be helpful in recognition of this diagnosis. In our case the posterior anomalies of the ribs were difficult to see even by 3D ultrasound and spiral CT, but the hemivertebrae were demonstrated clearly.
According to Wong, there is only one antenatal diagnosis of spondylocostal dysplasia by 3D made by Hull et al in 2001 . To our knowledge there are only three studies reporting the prenatal diagnosis of the Jarcho-Levin syndrome in patients without a risk for the condition [4-6] and only one author made a precise diagnosis in the first trimester .
The differential diagnosis of a fetus with vertebral, rib, cardiac and renal anomalies include the following diagnosis [8-9]:
Costovertebral segmentation defects with mesomelia (COVESDEM association): a mesomelia is also present;
Dyssegmental dysplasia (or Silverman-Handmaker type): is differentiated from spondylocostal dysplasia by the presence of micromelia with reduced mobility, bowing of the long bones and irregular vertebral bodies. Other sonographic findings are cleft palate, micrognathia and hydronephrosis with ventriculomegaly;
Spondyloepiphyseal dysplasia: differentiates from spondylothoracic and spondylocostal dysplasias by the lack of mineralization of the epiphyses and although shortening of the vertebral bodies is present, the vertebral column is not disorganized ;
Goldenhar syndrome or oculo-auriculo-vertebral syndrome: there is a mandibular hypoplasia with abnormalities of the auricle, cleft lip or/and cleft palate, and vertebral and ribs anomalies;
VACTERL association: Vertebral defect, Anal atresia, Cardiac anomalies, Tracheoesophageal fistula, Renal anomalies and Limb anomalies are present.
Associated anomalies can include a prominent occiput, a microcephaly, a cleft palate, a neural tube defect, a lordosis, an abdominal wall defect, the anal anomalies, urinary tract anomalies, longs arms, syndactyly, camptodactyly, and hernias .
Jarcho-Levin syndrome is nearly always lethal condition. Death occurs in the neonatal period or in early infancy due to pulmonary insufficiency. Spondylocostal dysplasia (spondylothoracic dysplasia type II) carries a better prognosis, dependent of vertebral and rib malformations and other malformations. Modern respiratory technologies have improved survival of infants with the spondylocostal dysplasia. Nevertheless, infants who survive beyond early childhood, have progressive scoliosis, impairment of foot nerves, neurological dysfunction and paraplegia secondary to spinal cord compression.
Prenatal findings of some skeletal malformations of the spine should encourage us also to pay attention to the morphology of the ribs and to look for some extraskeletal malformations. Obstetric and family history should be reviewed and chromosomal studies are frequently indicated. 3D ultrasonography can help to make more precise diagnosis and can help to give a better imagination of the anomalies to the parents. This will help in their decision-making process regarding the continuation or termination of the pregnancy.
2. Wong G., Levine D. Jarcho-Levin syndrome: two consecutive pregnancies in a Puerto-Rican couple. Ultrasound Obstet Gynecol 1998;12: 70-3.
3. Wong G.Y., Wong S.F., Ng W.F. Three-dimensional ultrasound findings of spondylo-costal dysostosis in the second trimester of pregnancy. Ultrasound Obstet Gynecol 2006; 27: 580-2.
4. Shehata S.M., El-Banna I., Gaber A.A., El-Samongy A.M. Spondylo-thoracic dysplasia with diaphragmatic defect: a case report with literature review. Surg J Pediatr Surg 2000; 10: 337-9.
5. Sallout B.I., D"Agostini D.A., Pretorius D.H. Prenatal diagnosis of spondylocostal dysostosis with 3-dimensional ultrasonography. J Ultrasound Med 2004; 25: 539-43.
6. Kauffman E., Roman H., Barau G., Dumas H., Laffitte A., Fourmaintraux A., Bintner M., Randrianaivo H. Case report: A prenatal case of Jarcho-Levin syndrome diagnosed during the first trimester of pregnancy. Prenat Diagn 2003; 23: 163-5.
7. Del Rio Holgado M., Martinez M., Gomez O., Casals G., Bargallo N., Fortuny A., Puerto B. Ultrasonographic diagnosis of Jarcho-Levin syndrome at 20 WG in a fetus without previous family history. Fetal diagn Ther 2005; 20: 136-40.
8. Hull A.D., James G., Pretorius D.H. Detection of Jarcho-Levin sydnrome at 12 WG by nuchal translucencyscreening and three-dimensional ultrasound. Prenat Diagn 2001; 21: 390-4.
9. Ngo C., Viot G., Aubry M.C., Tsatsaris V., Grange G., Cabrol D., Pannier E. First-trimester ultrasound diagnosis of skeletal dysplasia associated with inccreased nuchal translucency thikness. Ultrasound Obstet Gynecol 2007; 30: 221-6.