Most patients with idiopathic membranous nephropathy (IMN) have IgG4 autoantibodies against phospholipase A2 receptor (PLA2R). C3 and C5b-9 are found in immune deposits of IMN kidney biopsy specimens, but the pathway of complement activation in IMN remains elusive. We report the case of a patient who developed IMN with intense staining for PLA2R, IgG4, C3, C5b-9, factor B, and properdin and very weak staining for C1q, C4d, and IgG1. Measurement of mannan binding lectin (MBL) antigenic level and activity revealed MBL deficiency. Genotyping revealed a heterozygous (A/C) polymorphism in codon 57 of MBL2 exon 1 associated with homozygous and heterozygous variations in the promoter region at -550 (L/L) and -221 (X/Y), respectively, suggesting that the patient harbored the LXA/LYC haplotypes linked to MBL deficiency. Genetic sequencing in 77 consecutive patients with IMN identified four patients with MBL2 promoter and coding region variations associated with MBL deficiency and the same complement pattern in immune deposits as the index patient. In contrast, patients with wild-type MBL2 had immune deposits with intense Cd4 staining. Thus, IMN can develop in patients with complete MBL deficiency, with complement activated mainly by the alternative pathway, whereas the lectin pathway is also activated in those with wild-type MBL2.

Allelotyping of locus 4q12, which contains the c-kit gene, could help pediatric osteosarcoma prognostic screening and showed a strong correlation with overexpression of c-kit protein. These results allowed us to hypothesize that, in some cases, a mutation of c-kit gene could lead to a protein overexpression.

Objective: Campomelic dysplasia (CD) is a rare skeletal dysplasia characterized by marked femoral and tibial angulations, hypoplasic scapulae, normal upper limbs and sex reversal in 3/4 of 46,XY fetuses. Most cases are lethal in the neonatal period. Heterozygous mutations in the SOX9 gene are responsible for CD. The diagnosis is not usually made until the mid-second trimester or later. Methods: We describe 2 cases of CD suspected by ultrasonography in the first trimester. Results: The 2 cases presented with hygroma colli along with anomalies in the lower but not the upper limbs. Terminations of pregnancy were obtained at 14+3 and 20+6 gestational weeks. Fetopathological examinations confirmed sonographic findings. Conclusion: When first trimester hygroma colli is accompanied by specific findings of the lower limbs, the diagnosis of CD can be investigated through SOX9 mutation analysis.