OBJECTIVE: To explore the genetic basis for a Chinese pedigree affected with amyloidosis cutis dyschromica. METHODS: High-throughput sequencing was carried out for the proband. Bioinformatic analysis was used to identify the pathogenic variants. The result was verified by Sanger sequencing. RESULTS: A homozygous nonsense variant c.565C>T (p.Arg189X) of the GPNMB gene was identified in the proband, his elder brother and younger sister, which resulted a truncated protein with loss of function. The father of the proband was a heterozygous carrier for the variant. The genotype of his mother was unknown since she had passed away. Based on the American College of Medical Genetics and Genomics standards and guidelines, the c.565C>T variant was predicted to be likely pathogenic (PS3+ PM2+ PP1+PP3). CONCLUSION The novel homozygous GPNMB variant probably underlay the amyloidosis cutis dyschromica in this pedigree. Above finding has expanded the spectrum of GPNMB gene variants.
Amyloidosis, Familial/genetics* ; China ; Female ; Homozygote ; Humans ; Male ; Membrane Glycoproteins/genetics* ; Mutation ; Pedigree

OBJECTIVETo study the disease gene in a family with hereditary vitreous amyloidosis.

METHODSA family with hereditary vitreous amyloidosis was investigated. Blood samples were collected from 4 members of this family including 3 patients and 1 asymptomatic individual. Genomic DNA was extracted from peripheral blood sample and subjected to amplification of 4 exons of transthyretin (TTR) gene. The PCR products were purified and subjected to direct sequencing. A total of 150 unrelated individuals were used as controls.

RESULTSA heterozygous mutation G to C at codon 103 in exon 3 of TTR gene (Gly103Arg) was detected in all 4 members of the family but not in the unrelated controls.

CONCLUSIONThe heterozygous Gly103Arg mutation of TTR gene may be related to the development of hereditary vitreous amyloidosis in this family.

Amyloidosis, Familial ; genetics ; Base Sequence ; Exons ; genetics ; Female ; Heterozygote ; Humans ; Male ; Molecular Sequence Data ; Mutation ; Pedigree ; Prealbumin ; genetics

Hereditary gelsolin amyloidosis (HGA) is an autosomal dominant hereditary disease characterized by corneal lattice dystrophy, peripheral neuropathy, and cutis laxa. So far, no Korean patients with HGA have been reported. A 58-yr-old man presented with involuntary facial twitching, progressive bilateral facial weakness, and tongue atrophy. His mother, maternal uncle, two sisters, and son suffered from the same symptoms. Electrophysiological studies revealed signs of chronic denervation in the cervical and lumbar regions, mild sympathetic autonomic dysfunction, and bilateral facial nerve dysfunction. Diagnostic whole-exome sequencing (WES) revealed a p.D214Y heterozygous mutation in the gelsolin gene in affected members. We present the first report of a Korean family with HGA diagnosed by WES. WES facilitated a clinical diagnosis of HGA in patients with undiagnosed neuropathies.
Amyloidosis, Familial/diagnosis/*genetics ; Asian Continental Ancestry Group/*genetics ; Base Sequence ; DNA Mutational Analysis ; Gelsolin/*genetics ; Genotype ; Heterozygote ; Humans ; Male ; Middle Aged ; Pedigree ; Polymorphism, Single Nucleotide ; Republic of Korea

OBJECTIVE: To explore the pathological characteristics and significance of RET proto-oncogene screening in multiple endocrine neoplasia type 2A (MEN2A) with cutaneous lichen amyloidosis (CLA). METHODS: Clinical data of 51 members from 7 unrelated pedigrees of MEN2A-CLA were collected. Systemic clinical investigations including biochemical testing, imaging examination, germline RET variant screening and histopathological examination were carried out. RESULTS: RET gene variants were detected in 28 patients with MEN2A (C634G/F/R/S/W and C611Y) including 12 males and 16 females, with the mean age of diagnosis being (41.1 ± 18.3) years old, which were consistent with their clinical manifestations. The incidence of medullary thyroid carcinoma (MTC), pheochromocytoma (PHEO), hyperparathyroidism (HPTH) and CLA among 28 MEN2A patients were 89.3%, 28.6%, 7.1% and 28.6%, respectively. Comparison of the incidence of MTC/PHEO/HPTH and CLA between C611Y and C634G/F/R/S/W, only PHEO and CLA in C611Y were lower than those in C634G/F/R/S/W (P < 0.05; P < 0.05). Among 8 patients with CLA, the male to female ratio was 2 : 6. The clinical features included pruritus in the interscapular region and presence of dry, thickened, scaly, brown pigment, clustered or desquamate-like plaques. The mean onset age of CLA [(18.4 ± 4.6) years] versus the mean age at diagnosis of CLA or MEN2A were significantly different (P < 0.001; P < 0.001). CONCLUSION MEN2A-CLA may be the early clinical manifestation of MEN2A and most frequently occurred along with RET-C634 variant. To facilitate the recognition of MEN2A-CLA, to combine family investigation and screening of RET variant are helpful for early diagnosis and standardized treatment, which can improve the long-term outcome of MEN2A-specific tumors.
Adolescent ; Adrenal Gland Neoplasms ; Adult ; Amyloidosis, Familial ; Carcinoma, Neuroendocrine ; China ; Female ; Humans ; Lichens ; Male ; Middle Aged ; Multiple Endocrine Neoplasia Type 2a/genetics* ; Pheochromocytoma ; Proto-Oncogene Proteins c-ret/genetics* ; Skin Diseases, Genetic ; Thyroid Neoplasms/genetics* ; Young Adult