Type 2 familial partial lipodystrophy (FPLD2) is a laminopathic lipodystrophy due to pathogenic variants in the LMNA gene. Its rarity implies that it is not well-known. The aim of this review was to explore the published data regarding the clinical characterisation of this syndrome in order to better describe FPLD2. For this purpose, a systematic review through a search on PubMed until December 2022 was conducted and the references of the retrieved articles were also screened. A total of 113 articles were included. FPLD2 is characterised by the loss of fat starting around puberty in women, affecting limbs and trunk, and its accumulation in the face, neck and abdominal viscera. This adipose tissue dysfunction conditions the development of metabolic complications associated with insulin resistance, such as diabetes, dyslipidaemia, fatty liver disease, cardiovascular disease, and reproductive disorders. However, a great degree of phenotypical variability has been described. Therapeutic approaches are directed towards the associated comorbidities, and recent treatment modalities have been explored. A comprehensive comparison between FPLD2 and other FPLD subtypes can also be found in the present review. This review aimed to contribute towards augmenting knowledge of the natural history of FPLD2 by bringing together the main clinical research in this field.

Severe hypokalaemia causing rhabdomyolysis (RML) in primary aldosteronism (PA) is a rare entity, and only a few cases have been reported over the last four decades. This systematic review and case report aims to gather all published data regarding a hypokalaemic RML as presentation of PA in order to contribute to the early diagnosis of this extremely rare presentation. With the use of PubMed Central, EMBASE, and Google Scholar, a thorough internet-based search of the literature was conducted to identify articles and cases with RML secondary to hypokalaemia due to PA between June 1976 and July 2023. The case study concerns a 68-year-old male patient with hypokalaemic RML at presentation of PA. In the systematic review of the literature, 37 cases of RML secondary to hypokalaemia due to PA have been reported to date. In summary, the median age was 47.5 years, the male/female ratio was 17/21, all patients presented symptoms (weakness and/or myalgia), all the patients were hypertensive, and only four patients had complications with acute kidney injury (AKI). Although PA rarely presents with RML, it should be suspected when marked hypokalaemia and hypertension are also present. Early detection and management are essential to reduce the frequency of manifestations such as AKI.

Lipodystrophic laminopathies are a group of ultra-rare disorders characterised by the presence of pathogenic variants in the same gene (LMNA) and other related genes, along with an impaired adipose tissue pattern and other features that are specific of each of these disorders. The most fascinating traits include their complex genotype-phenotype associations and clinical heterogeneity, ranging from Dunnigan disease, in which the most relevant feature is precisely adipose tissue dysfunction and lipodystrophy, to the other laminopathies affecting adipose tissue, which are also characterised by the presence of signs of premature ageing (Hutchinson Gilford-progeria syndrome, LMNA-atypical progeroid syndrome, mandibuloacral dysplasia types A and B, Nestor-Guillermo progeria syndrome, LMNA-associated cardiocutaneous progeria). This raises several questions when it comes to understanding how variants in the same gene can lead to similar adipose tissue disturbances and, at the same time, to such heterogeneous phenotypes and variable degrees of metabolic abnormalities. The present review aims to gather the molecular basis of adipose tissue impairment in lipodystrophic laminopathies, their main clinical aspects and recent therapeutic strategies. In addition, it also summarises the key aspects for their differential diagnosis.

Acquired generalised lipodystrophy (AGL) is a rare disorder characterised by the gradual loss of fat that tends to generalise over time, the origin of which is still not fully clarified. The aim of this study was to offer a detailed description of seven patients with AGL (five women, 33.8 ± 18.6 years of age), evaluated over the last 14 years, in order to augment the knowledge of this disorder. The onset of the phenotype occurred during childhood and adolescence in five cases, and in adulthood in two cases. Three patients reported infections or vaccine administration prior to the development of lipodystrophy, and two subjects reported nodular swelling. The most frequent physical features were phlebomegaly, umbilical protrusion/hernia, and acanthosis nigricans. Skinfolds and body composition analysis showed the generalised absence of fat, with the exception of one patient in whom fat loss was spared in the trunk. The loss of fat in the palms/soles was observed in five subjects. Regarding metabolic comorbidities, throughout follow-up, two patients developed type 1 diabetes and one type 2 diabetes; three also presented hypertriglyceridaemia, one of whom developed acute pancreatitis, and no macrovascular complications were observed. Only one patient showed decreased complement C4. Autoimmunity was present in all cases, and six patients manifested Hashimoto’s thyroiditis, type 1 diabetes, autoimmune hepatitis, and/or celiac disease. Thus, there are certain clinical characteristics of AGL that may be considered important diagnostic criteria to differentiate this disorder from other lipodystrophy subtypes.

Seipin, a protein encoded by the BSCL2 gene, plays a crucial role in lipid metabolism, and some pathogenic biallelic variants cause lipodystrophy and associated metabolic disorders. This study investigates liver pathology and dysregulation of the FGF21 signalling pathway in two mouse models: Bscl2^−/− (knock-out) and Bscl2^Celia/Celia (knock-in). We evaluated liver histopathology using H&E and Oil red O staining, assessed hepatic triglyceride levels via enzymatic assays, and analyzed gene expression of key FGF21-related components (Fgf21, Ppargc1a, Fgfr1, and Klb) using quantitative real-time PCR. The liver histology was scored using the NAFLD activity score (NAS) system. Both models exhibited hepatic steatosis and inflammatory features. The Bscl2^−/− mice showed more pronounced liver damage, including ballooning degeneration and fibrosis. Gene expression analysis revealed a significant increase in Fgf21 in both models, suggesting an adaptive response to liver injury. Notably, Fgfr1 and Ppargc1a expression was moderately elevated in severe neurologically affected mice showing less hepatic involvement, suggesting a potential adaptive or protective association of these genes with reduced steatosis. Seipin deficiency leads to metabolic-associated steatotic liver disease and dysregulated FGF21 signalling. These findings provide insight into the pathophysiological mechanisms of lipodystrophy and liver disease and suggest that the FGF21 pathway could be a therapeutic target for treating seipin-related metabolic disorders.

Adrenal mixed corticomedullary tumors (MCMTs) are rare lesions showing a mixture of two cell populations of cortical and medullary lineage. We describe an MCMT case presented in a 56-year-old woman with a history of arterial hypertension and high levels of aldosterone, accompanied by a review of the literature. The adrenalectomy specimen showed a well-circumscribed nodule of 30 mm in size, containing 60% of cells with a cortical phenotype (positive for α-inhibin and melan-A) and 40% of cells with a medullary phenotype (positive for chromogranin-A, GATA-3 and somatostatin receptor 2). There was no significant mitotic activity, necrosis, nor lymphovascular invasion. The GNAS p.(Arg844Cys) mutation, as well as variants of uncertain significance AKAP13 p.(His641Pro) and EPAS1 p.(Ser478del) were detected in the tumor. MCMT is more common in women (75%) with a mean age of 46.6 years (range 16–78). Most patients present with hypertension (79%), frequently associated with Cushing’s syndrome, (39%), diabetes (21%), aldosteronism (15%), and/or hyperandrogenism (6%). Laboratory data showed elevated levels of both cortisol and cathecholamines and/or their metabolites in more than 50% of cases, supporting the dual nature of the tumor. Most MCMTs are benign, but aggressive behavior was detected in four (12%) cases, all of them showing large size (80–220 mm), poor delimitation, venous invasion, necrosis, and/or high proliferation rates. The pathogenesis is unknown, but our findings suggest a tumor histogenesis from the cortical cellular component through the regulation of the protein kinase A pathway and secondary proliferation of the medullary component.