Novel FGFR1 Variants Are Associated with Congenital Scoliosis

COL11A2 as a candidate gene for vertebral malformations and congenital scoliosis

Human vertebral malformations (VMs) have an estimated incidence of 1/2000 and are associated with significant health problems including congenital scoliosis (CS) and recurrent organ system malformation syndromes such as VACTERL (vertebral anomalies; anal abnormalities; cardiac abnormalities; tracheo-esophageal fistula; renal anomalies; limb anomalies). The genetic cause for the vast majority of VMs are unknown. In a CS/VM patient cohort, three COL11A2 variants (R130W, R1407L and R1413H) were identified in two patients with cervical VM. A third patient with a T9 hemivertebra and the R130W variant was identified from a separate study. These substitutions are predicted to be damaging to protein function, and R130 and R1407 residues are conserved in zebrafish Col11a2. To determine the role for COL11A2 in vertebral development, CRISPR/Cas9 was used to create a nonsense mutation (col11a2L642*) as well as a full gene locus deletion (col11a2del) in zebrafish. Both col11a2L642*/L642* and col11a2del/del mutant zebrafish exhibit vertebral fusions in the caudal spine, which form due to mineralization across intervertebral segments. To determine the functional consequence of VM-associated variants, we assayed their ability to suppress col11a2del VM phenotypes following transgenic expression within the developing spine. While wildtype col11a2 expression suppresses fusions in col11a2del/+ and col11a2del/del backgrounds, patient missense variant-bearing col11a2 failed to rescue the loss-of-function phenotype in these animals. These results highlight an essential role for COL11A2 in vertebral development and support a pathogenic role for two missense variants in CS.

Cosmetic evaluation in type II congenital scoliosis with long-spanned curve: a case-matched comparison with adolescent idiopathic scoliosis

Background

There is an acknowledged discrepancy between radiographic and cosmetic parameters for patients with adolescent idiopathic scoliosis (AIS). However, no study has specifically evaluated cosmesis in patients with congenital scoliosis (CS). Therefore, the purpose of this study was to identify the cosmetic differences between patients with CS and case-matched patients with AIS and to investigate the correlation between radiological measurements and clinical cosmetic assessment indices.

Methods

A total of 37 adolescents with CS and 37 sex-, age-, and curve magnitude-matched patients with AIS were included. Cobb angle, shoulder height difference (SHD), coronal balance (CB), T1 tilt, first rib angle (FRA), clavicle angle (CA), clavicle-rib cage intersection (CRCI), and apical vertebra translation (AVT) were measured in the full X-ray of the spine. Shoulder area index 1 (SAI1), shoulder area index 2 (SAI2), shoulder angle (SA), axilla angle (AA), thoracolumbar area index (TLAI), and right and left waist angle difference (RLWAD) were measured on the clinical images from a posterior view. Hump index (HI) was measured in the forward bending photography. All patients completed the Scoliosis Research Society-22 (SRS-22) questionnaire.

Results

No significant difference was noted in the radiographic parameters between the AIS and CS groups (P>0.05). However, patients with CS exhibited significantly lower SAI1 (0.91 vs. 0.98; P=0.002) and SAI2 (0.85 vs. 0.95; P=0.001) than did the patients with AIS. The SRS-22 scores for self-image and mental health in patients with CS were significantly lower than those in patients with AIS (P<0.05). The correlation coefficients with statistical significance between radiographic and cosmetic measurements in patients with CS and those with AIS ranged from -0.493 to 0.534 and from -0.653 to 0.717, respectively. None of the correlation coefficients exceeded 0.8, indicating that the current radiological indices only exhibited a limited level of consistency with patients' cosmesis.

Conclusions

As compared with age-, gender-, and curve pattern-matched patients with AIS, patients with CS exhibited worse cosmesis and had clinically significantly lower SRS-22 scores despite having relatively small clinical differences. Although the radiographic parameters may not always align with clinical presentation, this discrepancy could be observed in both patients with CS and those with AIS.