Genotype-phenotype relationships in Berardinelli-Seip congenital lipodystrophy

Area of Science:

• Genetics
• Endocrinology
• Metabolic Disorders

Background:

• Berardinelli-Seip congenital lipodystrophy (BSCL) is a rare, severe autosomal recessive disorder.
• Adverse metabolic consequences include hepatic dysfunction, hyperlipidaemia, diabetes mellitus, and hypertrophic cardiomyopathy.
• Previous studies identified BSCL1 on chromosome 9 and BSCL2 (seipin) on chromosome 11 as causative genes.

Purpose of the Study:

• To investigate genotype/phenotype relationships in 70 BSCL subjects from diverse ethnic backgrounds.
• To compare the clinical manifestations and severity between BSCL1, BSCL2, and other forms (BSCLX).
• To highlight the importance of molecular diagnosis for genetic counseling.

Main Methods:

• Genotype/phenotype correlation study.
• Analysis of 70 affected subjects from 44 unrelated pedigrees.
• Comparison of morbidity prevalence, disease severity, and specific complications (e.g., intellectual impairment) across different BSCL genetic subtypes.

Main Results:

• Hepatic dysfunction, hyperlipidaemia, diabetes mellitus, and hypertrophic cardiomyopathy were prevalent in all BSCL subtypes.
• BSCL2 showed a more severe phenotype than BSCL1, with higher rates of premature death and less frequent partial/delayed lipodystrophy onset.
• Intellectual impairment was significantly more prevalent in BSCL2 subjects (OR 17.0, p<0.0001) compared to BSCL1 or BSCLX.

Conclusions:

• BSCL2 is associated with increased mortality and intellectual impairment compared to BSCL1.
• Molecular diagnosis is crucial for understanding BSCL subtypes and guiding genetic counseling.
• Understanding genotype-phenotype correlations in BSCL is essential for patient management and prognosis.