Natural History of Congenital Generalized Lipodystrophy: A Nationwide Study From Turkey

CONTEXT

Congenital generalized lipodystrophy (CGL) is a rare autosomal recessive disorder characterized by near-total lack of body fat.

OBJECTIVE

We aimed to study natural history and disease burden of various subtypes of CGL.

DESIGN

We attempted to ascertain nearly all patients with CGL in Turkey.

SETTING

This was a nationwide study.

PATIENTS OR OTHER PARTICIPANTS

Participants included 33 patients (22 families) with CGL and 30 healthy controls.

MAIN OUTCOME MEASURE(S)

We wanted to ascertain genotypes by sequencing of the known genes. Whole-body magnetic resonance imaging was used to investigate the extent of fat loss. Metabolic abnormalities and end-organ complications were measured on prospective follow-up.

RESULTS

Analysis of the AGPAT2 gene revealed four previously reported and four novel mutations (CGL1; c.144C>A, c.667_705delinsCTGCG, c.268delC, and c.316+1G>T). Analysis of the BSCL2 gene revealed four different homozygous and one compound heterozygous possible disease-causing mutations (CGL2), including four novel mutations (c.280C>T, c.631delG, c.62A>T, and c.465-468delGACT). Two homozygous PTRF mutations (c.481-482insGTGA and c.259C>T) were identified (CGL4). Patients with CGL1 had preservation of adipose tissue in the palms, soles, scalp, and orbital region, and had relatively lower serum adiponectin levels as compared to CGL2 patients. CGL4 patients had myopathy and other distinct clinical features. All patients developed various metabolic abnormalities associated with insulin resistance. Hepatic involvement was more severe in CGL2. End-organ complications were observed at young ages. Two patients died at age 62 years from cardiovascular events.

CONCLUSIONS

CGL patients from Turkey had both previously reported and novel mutations of the AGPAT2, BSCL2, and PTRF genes. Our study highlights the early onset of severe metabolic abnormalities and increased risk of end-organ complications in patients with CGL.

Should patients with Down syndrome be screened for testicular microlithiasis?

BACKGROUND

Testicular microlithiasis (TM) is a rare condition characterized by asymptomatic calcification of seminiferous tubules and is considered as a precursor of testicular germ cell tumors. The prevalence of TM has been reported higher in patients with Down syndrome (DS) than general population. Our aim was to determine the prevalence of TM in our patients with DS.

PATIENTS AND METHODS

Male patients with DS confirmed by chromosomal analysis were prospectively evaluated using high resonance ultrasound. For every patient with DS, an age-matched healthy non-DS volunteer was recruited and the results were compared.

RESULTS

A total of 50 testes from 25 patients between the age of newborn and 19.3 years were studied. While nine patients with DS (36%) had TM, none of controls had TM. Mean testicular volumes (TVs) of patients with DS did not differ significantly from the control group. In DS group, patients with TM were significantly older than patients without TM (mean age was 8.44 years [range, 2.0-19.3 years] and 2.39 years [range, 0.1-12.1 years], respectively, p = 0.002). TM was found positively correlated with age (r = 0.568, p = 0.003). Cryptorchidism was found in five patients in DS group (three unilateral and two bilateral) and in two controls (one unilateral and one bilateral). Of the nine patients with TM, only one patient had cryptorchidism; thus, TM was not found to be related with cryptorchidism. All the nine patients with DS and TM had normal serum levels of α-fetoprotein and β-human chorionic gonadotropin.

CONCLUSION

On the basis of the high prevalence found in our study, we suggest that all male patients with DS should be screened for TM in childhood.