Gestational and neonatal outcomes of women with partial Dunnigan lipodystrophy

Introduction

Lipodystrophies are a group of disorders characterized by selective and variable loss of adipose tissue, which can result in an increased risk of insulin resistance and its associated complications. Women with lipodystrophy often have a high frequency of polycystic ovary syndrome (PCOS) and may experience gynecological and obstetric complications. The objective of this study was to describe the gestational outcomes of patients with familial partial lipodystrophy type 2 (FPLD2) at a reference center with the aim of improving the understanding and management of pregnant women affected by this condition.

Methods

This was a retrospective analysis of data obtained from questionnaires regarding past pregnancies and a review of medical records from the beginning of follow-up in outpatient clinics.

Results

All women diagnosed with FPLD2 who had previously become pregnant were included in this study (n=8). The women in the study experienced pregnancies between the ages of 14 and 38 years, with an average of 1.75 children per woman. The pregnancies in question were either the result of successful conception within 12 months of attempting to conceive or unplanned pregnancies. During pregnancy, two women (25%) were diagnosed with gestational diabetes mellitus (GDM), one (12.5%) with gestational hypothyroidism, and one (12.5%) with preeclampsia. Among the 17 pregnancies, two miscarriages (11.8%) occurred, and five cases (29.4%) of macrosomia were observed. Four instances of premature birth and an equal number of neonatal hypoglycemia cases were recorded. The reported neonatal complications included an unspecified malformation, respiratory infection, and two neonatal deaths related to heart malformation and respiratory distress syndrome.

Conclusion

Our data showed a high frequency of fetal complications in women with FPLD2. However, no instances of infertility or prolonged attempts to conceive have been reported, highlighting the significance of employing effective contraception strategies to plan pregnancies at optimal times for managing metabolic comorbidities.

Familial partial lipodystrophy type 2 and obesity, two adipose tissue pathologies with different inflammatory profiles

INTRODUCTION

The transition to metabolically unhealthy obesity (MUO) is driven by the limited expandability of adipose tissue (AT). Familial Partial Lipodystrophy type 2 (FPLD2) is an alternative model for AT dysfunction that is suitable for comparison with obesity. While MUO is associated with low-grade systemic inflammation, studies of inflammation in FPLD2 have yielded inconsistent results. Consequently, comparison of inflammation markers between FPLD2 and obesity is of great interest to better understand the pathophysiological defects of FPLD2.

OBJECTIVE

To compare the levels of inflammatory biomarkers between a population of patients with FPLD2 due to the same 'Reunionese' LMNA variant and a population of patients with obesity (OB group).

METHODS

Adiponectin, leptin, IL-6, TNF-α and MCP-1 plasma levels were measured by enzyme-linked immuno assays for 60 subjects with FPLD2 and for 60 subjects with obesity. The populations were closely matched for age, sex, and diabetic status.

RESULTS

Metabolic outcomes were similar between the two populations. Adiponectinemia and leptinemia were lower in the FPLD2 group than in the OB group (p < 0.01 for both), while MCP-1 levels were higher in the FPLD2 than in the OB group (p < 0.01). Levels of other inflammatory markers were not significantly different.

CONCLUSIONS

Insulin-resistant patients with FPLD2 and obesity share common complications related to AT dysfunction. Inflammatory biomarker analyses demonstrated that MCP-1 levels and adiponectin levels differ between patients with FPLD2 and patients with obesity. These two AT pathologies thus appear to have different inflammatory profiles.

Lipoatrophic diabetes in familial partial lipodystrophy type 2: From insulin resistance to diabetes

AIM

Subjects with Familial Partial Lipodystrophy type 2 (FPLD2) are at high risk to develop diabetes. To better understand the natural history and variability of this disease, we studied glucose tolerance, insulin response to an oral glucose load, and metabolic markers in the largest cohort to date of subjects with FPLD2 due to the same LMNA variant.

METHODS

A total of 102 patients aged > 18 years, with FPLD2 due to the LMNA 'Reunionese' variant p.(Thr655Asnfs*49) and 22 unaffected adult relatives with normal glucose tolerance (NGT) were enrolled. Oral Glucose Tolerance Tests (OGTT) with calculation of derived insulin sensitivity and secretion markers, and measurements of HbA1c, C-reactive protein, leptin, adiponectin and lipid profile were performed.

RESULTS

In patients with FPLD2: 65% had either diabetes (41%) or prediabetes (24%) despite their young age (median: 39.5 years IQR 29.0-50.8) and close-to-normal BMI (median: 25.5 kg/m² IQR 23.1-29.4). Post-load OGTT values revealed insulin resistance and increased insulin secretion in patients with FPLD2 and NGT, whereas patients with diabetes were characterized by decreased insulin secretion. Impaired glucose tolerance with normal fasting glucose was present in 86% of patients with prediabetes. Adiponectin levels were decreased in all subjects with FPLD2 and correlated with insulin sensitivity markers.

CONCLUSIONS

OGTT reveals early alterations of glucose and insulin metabolism in patients with FPLD2, and should be systematically performed before excluding a diagnosis of prediabetes or diabetes to adapt medical care. Decreased adiponectin is an early marker of the disease. Adiponectin replacement therapy warrants further study in FPLD2.

Diagnostic Value of Anthropometric Measurements for Familial Partial Lipodystrophy, Dunnigan Variety

CONTEXT

Familial partial lipodystrophy, Dunnigan variety (FPLD2) is a rare autosomal dominant disorder resulting from LMNA causal variants, which is characterized by loss of subcutaneous fat from the extremities and predisposition to metabolic complications. The diagnostic value of various anthropometric measurements for FPLD2 remains unknown.

OBJECTIVE

To determine specificity and sensitivity of anthropometric measurements for the diagnosis of FPLD2.

METHODS

We measured skinfold thickness and regional body fat by dual energy X-ray absorptiometry (DXA) in 50 adult females and 6 males with FPLD2 at UT Southwestern and compared their data with the sex- and age-matched controls from the National Health and Nutrition Examination Survey (NHANES) 1999-2010. We further compared data from 1652 unaffected females from the Dallas Heart Study and 23 females with FPLD2 from the National Institutes of Health with the NHANES data.

RESULTS

The DXA-derived lower limb fat (%) had the best specificity (0.995) and sensitivity (1.0) compared with the upper limb fat, truncal fat, the ratio of lower limb to truncal fat, and triceps skinfold thickness for adult females with FPLD2. The lower limb fat below 1st percentile of NHANES females had a false-positive rate of 0.0054 and a false negative rate of 0. The diagnostic value of anthropometric parameters could not be determined for males with FPLD2 due to small sample size.

CONCLUSIONS

The lower limb fat (%) is the best objective anthropometric measure for diagnosing FPLD2 in females. Women with below the 1st percentile lower limb fat should undergo genetic testing for FPLD2, especially if they have metabolic complications.

Homozygous and Heterozygous Nuclear Lamin A p.R582C Mutation: Different Lipodystrophic Phenotypes in the Same Kindred

Background: Dunnigan-type familial partial lipodystrophy (FPLD2) is a rare autosomal dominant disease caused by heterozygous mutations in the LMNA gene that results in regional loss of subcutaneous adipose tissue with onset in puberty. However, a generalized lipodystrophy phenotype has also been associated with heterozygous mutations in this gene, demonstrating the noticeable phenotypic heterogeneity of this disease. Methods: We report and describe clinical and metabolic features of four patients from the same family with the p.R582C LMNA mutation, three homozygous and one in the heterozygous state that present with three distinct lipodystrophic phenotypes. Results: Case description: The proband was a 12-year-old girl who developed severe subcutaneous fat atrophy in limbs and abdomen followed by a remarkable dorsocervical fat accumulation in adulthood along with diabetes at age 23. The proband's sister was a phenotypically normal girl who developed hypertriglyceridemia at age 8, progressive features of partial lipodystrophy at age 11, and diabetes at age 22. The proband's mother was first examined at age 32, presenting diabetes and a severe generalized lipodystrophic phenotype; she developed kidney failure at age 41 and died due to diabetic complications. The proband's father was a 50-year-old man with abdominal fat concentration that was initially considered phenotypically normal. Massively parallel sequencing using a platform of genes related to genetic lipodystrophies, followed by Sanger sequencing, revealed the transversion c.1744C>T at exon 11 of the LMNA gene (p.R582C) in the homozygous (mother and daughters) and heterozygous (father) states. Conclusion: We documented three distinct phenotypes of the homozygous and heterozygous p. R582C LMNA mutation in the same kindred, illustrating that FPLD2 linked to mutations in this gene is a disease of great clinical heterogeneity, possibly due to associated environmental or genetic factors.