METHODS: To understand the genetic factor in a family with GGE, we performed whole exome sequencing (WES) on a trio of a juvenile myoclonic epilepsy/febrile seizure (JME/FS) proband with JME/FS mother and healthy father. Sanger sequencing was carried out for validation of WES results and variant detection in other family members.
RESULTS: Predictably damaging variant found in affected proband and mother but absent in healthy father in SCN1A gene was found to be associated with generalized epilepsy and febrile seizure. The novel non-synonymous substitution (c.5753C>T, p.S1918F) in SCN1A was found in all family members with GGE, of which 4/8 were JME subtypes, and/or febrile seizure, while 3 healthy family member controls did not have the mutation. This mutation was also absent in 41 GGE patients and 414 healthy Malaysian Chinese controls.
CONCLUSION: The mutation is likely to affect interaction between the sodium channel and calmodulin and subsequently interrupt calmodulin-dependent modulation of the channel.
METHODS: Genome-wide linkage analysis was carried out on eight large extended families of NSCL/P with the total of 91 individuals among Malay population using microarray platform. Based on linkage analyses findings, copy number variation (CNV) of LPHN2, SATB2, PVRL3, COL21A1, and TOX3 were identified in four large extended families that showed linkage evidence using quantitative polymerase chain reaction (qPCR) as for a validation purpose. Copy number calculated (CNC) for each genes were determined with Applied Biosystems CopyCallerTM Software v2.0. Normal CNC of the target sequence expected was set at two.
RESULTS: Genome-wide linkage analysis had discovered several genes including TOX3 and COL21A1 in four different loci 4p15.2-p16.1, 6p11.2-p12.3, 14q13-q21, and 16q12.1. There was significant decreased, p
METHODS: An ethnographic investigation using purposive sampling to increase subject diversity was used to explore the range of beliefs about kinship and inheritance using Chinese-Australians as a case. Participants comprised a sample of 15 Chinese-Australians who had been recruited through several community-based organizations.
RESULTS: The level of acculturation does not correlate with holding beliefs about inheritance, kinship, and causes of hereditary cancer that are based on "Western" biomedical or traditional concepts. Mismatch between beliefs may exist within families that can impact participation in cancer genetic testing. Family history taking that underpins the surveillance, management, and referral to genetic counseling where there is a strong family history of breast, ovarian, or colorectal cancer can also be impacted unless recognition is made of the patrilineal concept of kinship prevalent in this Chinese-Australian community.
CONCLUSION: This community-based study confirmed and validated views and beliefs on inheritance and kinship and inherited cancer attributed to senior family members by Chinese-Australians who attended cancer genetic counseling. Barriers to communication can occur where there may be incompatibility within the family between "Western" and traditional beliefs. The findings were used to develop strategies for culturally competent cancer genetic counseling with Australian-Chinese patients. These include nonjudgmental incorporation of their belief systems into the genetic counseling process and avoidance of stereotyping. They have also influenced the development of genetics education materials to optimize family history taking.
SUMMARY: Background Mutation of the growth factor-independent 1B (GFI1B) fifth DNA-binding zinc-finger domain causes macrothrombocytopenia and α-granule deficiency leading to clinical bleeding. The phenotypes associated with GFI1B variants disrupting non-DNA-binding zinc-fingers remain uncharacterized. Objectives To determine the functional and phenotypic consequences of GFI1B variants disrupting non-DNA-binding zinc-finger domains. Methods The GFI1B C168F variant and a novel GFI1B c.2520 + 1_2520 + 8delGTGGGCAC splice variant were identified in four unrelated families. Phenotypic features, DNA-binding properties and transcriptional effects were determined and compared with those in individuals with a GFI1B H294 fs mutation of the fifth DNA-binding zinc-finger. Patient-specific induced pluripotent stem cell (iPSC)-derived megakaryocytes were generated to facilitate disease modeling. Results The DNA-binding GFI1B variant C168F, which is predicted to disrupt the first non-DNA-binding zinc-finger domain, is associated with macrothrombocytopenia without α-granule deficiency or bleeding symptoms. A GFI1B splice variant, c.2520 + 1_2520 + 8delGTGGGCAC, which generates a short GFI1B isoform that lacks non-DNA-binding zinc-fingers 1 and 2, is associated with increased platelet CD34 expression only, without quantitative or morphologic platelet abnormalities. GFI1B represses the CD34 promoter, and this repression is attenuated by different GFI1B zinc-finger mutations, suggesting that deregulation of CD34 expression occurs at a direct transcriptional level. Patient-specific iPSC-derived megakaryocytes phenocopy these observations. Conclusions Disruption of GFI1B non-DNA-binding zinc-finger 1 is associated with mild to moderate thrombocytopenia without α-granule deficiency or bleeding symptomatology, indicating that the site of GFI1B mutation has important phenotypic implications. Platelet CD34 expression appears to be a common feature of perturbed GFI1B function, and may have diagnostic utility.