1.Study on TYR gene variant from a pedigree with oculocutaneous albinism.
Yingzhen ZHANG ; Caihong JIN ; Min GUO ; Duofu LI ; Lianming CHAI ; Yang WU ; Donglu LI
Chinese Journal of Medical Genetics 2021;38(9):833-837
OBJECTIVE:
To analyze gene variants in a Chinese pedigree with oculocutaneous albinism (OCA).
METHODS:
Gene sequencing of the proband and his parents was performed using chip capture high-throughput sequencing and Sanger sequencing techniques, and PolyPhen-2, SIFT, MutationTaster, and FATHMM software were used to predict the function of new variants. At the same time,the pedigree and variant genes of 4 albinism patients from this pedigree were analyzed.
RESULTS:
Sequencing results showed that the proband's TYR gene (NM_000372) has c.230G>A (p.Arg77Gln) and c.120_121insG (p.Asp42GlyfsTer35) compound heterozygous variants. The proband's father carries c.230G>A heterozygous variant, and the mother carries c.120_121insG heterozygous variant, indicating that the proband's two variants are from his father and mother. The former is a known missense variant, which can cause abnormal or loss of the original function of the protein polypeptide chain. The latter c.120_121insG(p.Asp42GlyfsTer35) is an unreported frameshift variant of the TYR gene subregion (EX1; CDS1). PolyPhen-2, SIFT, MutationTaster and FATHMM predictions are all prompted as "harmful variants". This variant caused the amino acid encoded protein to terminate prematurely, producing a truncated protein, which eventually formed a 76-amino acid short-type TYR protein instead of the 529-amino acid wild-type TYR protein. Through the pedigree analysis, the four patients in the pedigree are all of the same type of compound heterozygous variants, and the disease-causing genes are all from the patient's parents. They belong to a special form of consanguineous marriage within 5 generations.
CONCLUSION
The compound heterozygous variants of c.230G>A (p.Arg77Gln) and c.120_121insG (p.Asp42GlyfsTer35) of the TYR gene may underlie the disease in this pedigree. The gene sequencing results enrich the variant spectrum of the TYR gene, and has facilitated molecular diagnosis for the patient.
Albinism, Oculocutaneous/genetics*
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Consanguinity
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Heterozygote
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Humans
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Mutation
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Pedigree
2.Association of CYP2C9 Genetic Variants with Vitiligo.
Abdullateef A ALZOLIBANI ; Ahmad AL ROBAEE ; Hani AL-SHOBAILI ; Fahad AL-SAIF ; Eman AL-MEKHADAB ; Ahmed A SETTIN
Annals of Dermatology 2014;26(3):343-348
BACKGROUND: Vitiligo is a depigmenting skin disorder in which genetic factors play an important role. OBJECTIVE: To examine the association of CYP2C9 *1/*2/*3 gene polymorphism with vitiligo. METHODS: In this case controlled study, 95 Saudi patients with vitiligo (50 men and 45 women), with a mean age of 27.3 years, were analyzed. Patients were compared to 86 healthy controls from the same locality (76 men and 10 women), with a mean age of 20.1 years. In all participants, DNA was extracted and processed for characterization of 2C9 *1/*2/*3 gene variants using real time-polymerase chain reaction. RESULTS: Vitiligo patients have a significantly higher CYP2C9 *3 allele carriage rate compared to controls (32.7% versus 4.7%, p=0.00, odds ratio=9.9, 95% confidence interval=3.3~29.6). On the other hand, frequencies of CYP2C9 *2 genotypes and alleles did not show any significant difference between vitiligo cases and controls. When the frequencies of CYP2C9 genotypes were compared among subgroups of age, gender, family history, and disease patterns, the cases with positive consanguinity had significantly higher frequencies of homozygous genotypes than others (p=0.029). CONCLUSION: CYP2C9 *3 allele carriage is probably associated with vitiligo susceptibility.
Alleles
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Case-Control Studies
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Consanguinity
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DNA
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Genotype
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Hand
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Humans
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Male
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Polymorphism, Genetic
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Skin
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Vitiligo*
3.A case of collodion baby.
Dong Il PARK ; To Hyi CHOI ; Jin Bok HWANG ; Chang Ho HAN ; Hye Li CUNG ; Young Dae KWON
Journal of the Korean Pediatric Society 1993;36(6):858-864
This is a rare typical case of collodion baby. The patient is a one-day-old newborn male who has been suffering from the tightly collodion or parchment-like coverings over the entire skin surface with ectropion, eclabion, fixed semiflexion position of the limbs and fissures on the flexual area. The family history was noncontributory with no consanguinity. This patient was desquamated from collodion-like membrane and returned to normal looking skin from the seventh day of life to one month. Diagnosis of collodion baby was established by clinical features and histopathological study. A brief review of literature was made.
Collodion*
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Consanguinity
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Diagnosis
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Ectropion
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Extremities
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Humans
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Infant, Newborn
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Male
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Membranes
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Skin
4.A Case of Nasu-Hakola Disease without Fractures or Consanguinity Diagnosed Using Exome Sequencing and Treated with Sodium Valproate.
Kiyohiro YAMAZAKI ; Yuta YOSHINO ; Yoko MORI ; Shinichiro OCHI ; Taku YOSHIDA ; Takashi ISHIMARU ; Shu Ichi UENO
Clinical Psychopharmacology and Neuroscience 2015;13(3):324-326
Nasu-Hakola disease (NHD) is a rare autosomal recessive neuropsychiatric disorder characterized by bone cysts, fractures, and cognitive impairment. Two genes are responsible for the development of NHD; TYROBP and TREM2. Although it presents with typical signs and symptoms, diagnosing this disease remains difficult. This case report describes a male with NHD with no family or past history of bone fractures who was diagnosed using exome sequencing. His frontal lobe psychiatric symptoms recovered partially following treatment with sodium valproate, but not with an antipsychotic.
Bone Cysts
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Consanguinity*
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Exome*
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Fractures, Bone
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Frontal Lobe
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Humans
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Male
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Sodium*
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Valproic Acid*
5.A case of acormelanosis progressiva.
Ho Seong LEE ; Chee Won OH ; Ki Beom PARK
Korean Journal of Dermatology 1993;31(4):624-627
Acromelanosis progressiva is a peculiar progressive pigmentary disorder characterized by intensely dark and sharply demarcated hyperpigmentation over the dorsa of fingers and toes, and the pigmentation rapidly spread proximally. A 19-year-old female had sharply demarcated symmetric dark aroarn macules on the dorsa of her hands and feet, forearms, lower legs, face and neck. These pigmentations at first appeared at the age of 5 on the dorsa of her fingers and toes, thereafter these pigmertatons spread progressively to the proximal portion of her body. Histologically, a proliferation of mela biocyte at the epidermal-dermal junction was seen, associated with mild hyperkeratosis. She was othervise normal on physical examination and had no family historv of consanguinity.
Consanguinity
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Female
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Fingers
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Foot
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Forearm
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Hand
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Humans
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Hyperpigmentation
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Leg
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Neck
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Physical Examination
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Pigmentation
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Toes
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Young Adult
6.Multiple Neurofibromatosis Manifesting Autosomal Dominant Ingeritance in a Single Family.
Korean Journal of Dermatology 1976;14(3):239-245
Multiple neurofibromatosis is known to be a genetic disease with the autosomal dominant inheritance pattern. In clinical practice, however, we can hardly ever find a case in which the autosomal dominant inheritance is demonstrable, because sporadic mutation is believed to cause about 50 % of the observed rnultiple neurofibromatosis cases, and because such patients show reduced fertility. The authors observed a family case in which the typical autosomal dominant inheritance could be demonstrated. Among 17 consanguinities of the 3 generations studied, 12 had developed multiple neurofibrornatosis. The presumed reason for the high incidence of the disease in the family studied is 2 fold: 1) The autosomal dominant gene responsible for the disease is highly penetrable. 2) The mutant gene responsible for the disease, for some unexplained reason, was transmitted from patient No. 1 to a.ll of her offsprings, instead of to only half of her offsprings, as would be expected. Multiple neurofibromatosis is known to be a genetic disease with the autosomal dominant inheritance pattern. In clinical practice, however, we can hardly ever find a case in which the autosomal dominant inheritance is demonstrable, because sporadic mutation is believed to cause about 50 % of the observed rnultiple neurofibromatosis cases, and because such patients show reduced fertility. The authors observed a family case in which the typical autosomal dominant inheritance could be demonstrated. Among 17 consanguinities of the 3 generations studied, 12 had developed multiple neurofibrornatosis. The presumed reason for the high incidence of the disease in the family studied is 2 fold: 1) The autosomal dominant gene responsible for the disease is highly penetrable. 2) The mutant gene responsible for the disease, for some unexplained reason, was transmitted from patient No. 1 to a.ll of her offsprings, instead of to only half of her offsprings, as would be expected. Multiple neurofibromatosis is known to be a genetic disease with the autosomal dominant inheritance pattern. In clinical practice, however, we can hardly ever find a case in which the autosomal dominant inheritance is demonstrable, because sporadic mutation is believed to cause about 50 % of the observed rnultiple neurofibromatosis cases, and because such patients show reduced fertility. The authors observed a family case in which the typical autosomal dominant inheritance could be demonstrated. Among 17 consanguinities of the 3 generations studied, 12 had developed multiple neurofibrornatosis. The presumed reason for the high incidence of the disease in the family studied is 2 fold: 1) The autosomal dominant gene responsible for the disease is highly penetrable. 2) The mutant gene responsible for the disease, for some unexplained reason, was transmitted from patient No. 1 to a.ll of her offsprings, instead of to only half of her offsprings, as would be expected.
Consanguinity
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Family Characteristics
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Fertility
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Genes, Dominant
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Humans
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Incidence
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Inheritance Patterns
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Neurofibromatoses*
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Neurofibromatosis 1
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Wills
7.Onset of hemangioma in a consanguineous pedigree.
Qingfeng LI ; Yanlin REN ; Junfeng LIU ; Jinli XU ; Lihua CHEN
Chinese Journal of Medical Genetics 2015;32(3):439-439
Adult
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Consanguinity
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Female
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Hemangioma
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genetics
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Humans
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Male
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Middle Aged
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Pedigree
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Young Adult
8.Analysis of a patient with early-onset Parkinson's disease and PARK7 gene variation.
Fei XIE ; Xiaosheng ZHENG ; Zhidong CEN ; Wei LUO
Chinese Journal of Medical Genetics 2019;36(10):957-960
OBJECTIVE:
To explore the genetic basis of a patient with early-onset Parkinson disease from a consanguineous family.
METHODS:
Homozygosity mapping and Sanger sequencing of cDNA were used to identify the causative mutation.
RESULTS:
A homozygous missense variation (c.56C>G, p.Thr19Arg) in the PARK7 gene was identified in the patient. In silico analysis suggested the c.56C>G variation to be pathogenic.
CONCLUSION
Homozygous c.56C>G variation of the PARK7 gene was the disease-causing variation in this family.
Consanguinity
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Homozygote
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Humans
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Mutation, Missense
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Parkinson Disease
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genetics
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Pedigree
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Protein Deglycase DJ-1
;
genetics
9.Identification of a novel variant of F5 gene in a consanguineous pedigree affected with inherited coagulation factor V deficiency.
Mohan LIU ; Yuan YANG ; Yunqiang LIU
Chinese Journal of Medical Genetics 2020;37(5):505-508
OBJECTIVE:
To explore the genetic basis for a consanguineous pedigree affected with inherited coagulation factor V deficiency.
METHODS:
Genomic DNA was extracted from peripheral blood samples from the pedigree and subjected to next generation sequencing for screening variants of the F5 gene. Suspected pathogenic variant was verified by using Sanger sequencing. Pathogenicity of the variant was evaluated according to ACMG guidelines.
RESULTS:
A homozygous frameshifting variant, c.4096delC (p.Leu1366Phefs*3), was identified in the F5 gene in the proband, which was confirmed to be derived from her consanguineous parents. This variant was absent in all databases including 10 000 in-house Chinese exome sequences. Based on the ACMG guidelines, the c.4096delC was predicted to be a pathogenic variant.
CONCLUSION
A novel pathogenic variant has been identified in the F5 gene in a consanguineous pedigree with inherited coagulation factor V deficiency, which has enriched the spectrum of F5 gene variants.
Consanguinity
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Factor V
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genetics
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Factor V Deficiency
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genetics
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Female
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Genetic Variation
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Humans
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Pedigree