TY - JOUR
T1 - Assessment of fibroblast nuclear morphology aids interpretation of LMNA variants
AU - van Tienen, Florence
AU - Lindsey, Patrick
AU - Kamps, Miriam
AU - Krapels, Ingrid
AU - Ramaekers, Frans
AU - Brunner, Han
AU - van den Wijngaard, Arthur
AU - Broers, Jos
N1 - Publisher Copyright:
© 2018, European Society of Human Genetics.
PY - 2019/3
Y1 - 2019/3
N2 - The phenotypic heterogeneity of Lamin A/C (LMNA) variants renders it difficult to classify them. As a consequence, many LMNA variants are classified as variant of unknown significance (VUS). A number of studies reported different types of visible nuclear abnormalities in LMNA-variant carriers, such as herniations, honeycomb-like structures and irregular Lamin staining. In this study, we used lamin A/C immunostaining and nuclear DAPI staining to assess the number and type of nuclear abnormalities in primary dermal fibroblast cultures of laminopathy patients and healthy controls. The total number of abnormal nuclei, which includes herniations, honeycomb-structures, and donut-like nuclei, was found to be the most discriminating parameter between laminopathy and control cell cultures. The percentage abnormal nuclei was subsequently scored in fibroblasts of 28 LMNA variant carriers, ranging from (likely) benign to (likely) pathogenic variant. Using this method, 27 out of 28 fibroblast cell cultures could be classified as either normal (n = 14) or laminopathy (n = 13) and no false positive results were obtained. The obtained specificity was 100% (CI 40-100%) and sensitivity 77% (46-95%). We conclude that assessing the percentage of abnormal nuclei is a quick and reliable method, which aids classification or confirms pathogenicity of identified LMNA variants causing formation of aberrant lamin A/C protein.
AB - The phenotypic heterogeneity of Lamin A/C (LMNA) variants renders it difficult to classify them. As a consequence, many LMNA variants are classified as variant of unknown significance (VUS). A number of studies reported different types of visible nuclear abnormalities in LMNA-variant carriers, such as herniations, honeycomb-like structures and irregular Lamin staining. In this study, we used lamin A/C immunostaining and nuclear DAPI staining to assess the number and type of nuclear abnormalities in primary dermal fibroblast cultures of laminopathy patients and healthy controls. The total number of abnormal nuclei, which includes herniations, honeycomb-structures, and donut-like nuclei, was found to be the most discriminating parameter between laminopathy and control cell cultures. The percentage abnormal nuclei was subsequently scored in fibroblasts of 28 LMNA variant carriers, ranging from (likely) benign to (likely) pathogenic variant. Using this method, 27 out of 28 fibroblast cell cultures could be classified as either normal (n = 14) or laminopathy (n = 13) and no false positive results were obtained. The obtained specificity was 100% (CI 40-100%) and sensitivity 77% (46-95%). We conclude that assessing the percentage of abnormal nuclei is a quick and reliable method, which aids classification or confirms pathogenicity of identified LMNA variants causing formation of aberrant lamin A/C protein.
KW - LAMIN A/C MUTATIONS
KW - DILATED CARDIOMYOPATHY
KW - PARTIAL LIPODYSTROPHY
KW - MUSCULAR-DYSTROPHY
KW - ENVELOPE ALTERATIONS
KW - PROGERIA-SYNDROME
KW - GENE
KW - PHENOTYPE
KW - EXPRESSION
KW - PRELAMIN
U2 - 10.1038/s41431-018-0294-0
DO - 10.1038/s41431-018-0294-0
M3 - Article
C2 - 30420677
SN - 1018-4813
VL - 27
SP - 389
EP - 399
JO - European Journal of Human Genetics
JF - European Journal of Human Genetics
IS - 3
ER -