Targeted massively parallel sequencing for congenital generalized lipodystrophy.

OBJECTIVE: Our aim is to establish genetic diagnosis of congenital generalized lipodystrophy (CGL) using targeted massively parallel sequencing (MPS), also known as next-generation sequencing (NGS). METHODS: Nine unrelated individuals with a clinical diagnosis of CGL were recruited. We used a customized panel to capture genes related to genetic lipodystrophies. DNA libraries were generated, sequenced using the Illumina MiSeq, and bioinformatics analysis was performed. RESULTS: An accurate genetic diagnosis was stated for all nine patients. Four had pathogenic variants in AGPAT2 and three in BSCL2. Three large homozygous deletions in AGPAT2 were identified by copy-number variant analysis. CONCLUSION: Although we have found allelic variants in only 2 genes related to CGL, the panel was able to identify different variants including deletions that would have been missed by Sanger sequencing. We believe that MPS is a valuable tool for the genetic diagnosis of multi-genes related diseases, including CGL.

Early-onset, progressive, frequent, extensive, and severe bone mineral and renal complications in multiple endocrine neoplasia type 1-associated primary hyperparathyroidism.

Differences in bone mineral density (BMD) patterns have been recently reported between multiple endocrine neoplasia type 1-related primary hyperparathyroidism (HPT/MEN1) and sporadic primary HPT. However, studies on the early and later outcomes of bone/renal complications in HPT/MEN1 are lacking. In this cross-sectional study, performed in a tertiary academic hospital, 36 patients cases with uncontrolled HPT from 8 unrelated MEN1 families underwent dual-energy X-ray absorptiometry (DXA) scanning of the proximal one-third of the distal radius (1/3DR), femoral neck, total hip, and lumbar spine (LS). The mean age of the patients was 38.9 ± 14.5 years. Parathyroid hormone (PTH)/calcium values were mildly elevated despite an overall high percentage of bone demineralization (77.8%). In the younger group (<50 years of age), demineralization in the 1/3DR was more frequent, more severe, and occurred earlier (40%; Z-score -1.81 ± 0.26). The older group (>50 years of age) had a higher frequency of bone demineralization at all sites (p < .005) and a larger number of affected bone sites (p < .0001), and BMD was more severely compromised in the 1/3DR (p = .007) and LS (p = .002). BMD values were lower in symptomatic (88.9%) than in asymptomatic HPT patients (p < .006). Patients with long-standing HPT (>10 years) and gastrinoma/HPT presented significantly lower 1/3DR BMD values. Urolithiasis occurred earlier (<30 years) and more frequently (75%) and was associated with related renal comorbidities (50%) and renal insufficiency in the older group (33%). Bone mineral- and urolithiasis-related renal complications in HPT/MEN1 are early-onset, frequent, extensive, severe, and progressive. These data should be considered in the individualized clinical/surgical management of patients with MEN1-associated HPT.

Bone mineral density analysis in patients with primary hyperparathyroidism associated with multiple endocrine neoplasia type 1 after total parathyroidectomy.

OBJECTIVE: Limited data have been reported on the effect of parathyroidectomy (PTx) on bone mineral density (BMD) in the setting of patients with hyperparathyroidism (HPT) associated with multiple endocrine neoplasia type 1 (MEN1). This study investigates the impact of total PTx on BMD in patients with HPT/MEN1. DESIGN AND PATIENTS: A case series study was performed in a tertiary academic hospital. A total of 16 HPT/MEN1 patients from six families harbouring MEN1 germline mutations were subjected to total PTx followed by parathyroid auto-implant in the forearm. MEASUREMENTS: Bone mineral density values were assessed using dual-energy X-ray absorptiometry. RESULTS: Before PTx, reduced BMD (Z-score <-2.0) was highly prevalent in the proximal one-third of the distal radius (1/3 DR) (50%), lumbar spine (LS) (43.7%), ultradistal radius (UDR) (43.7%), femoral neck (FN) (25%) and total femur (TF) (18.7%) in the patients. Fifteen months after PTx, we observed a BMD improvement in the LS (from 0.843 to 0.909 g/cm(2); +8.4%, P = 0.001), FN (from 0.745 to 0.798 g/cm(2); +7.7%, P = 0.0001) and TF (from 0.818 to 0.874 g/cm(2); +6.9%, P < 0.0001). No significant change was noticed in the 1/3 DR and UDR after PTx. CONCLUSIONS: This data confirmed BMD recovery in the LS and FN after PTx in HPT/MEN1 patients. We also documented a significant BMD increase in the TF and no change in both the 1/3 DR and UDR BMD after PTx. Our data suggest that LS and proximal femur are the most informative sites to evaluate the short-term BMD outcome after PTx in HPT/MEN1 subjects.