Final Thursday May 22, 2014 Take home No help 10% extra credit Due Monday May 26, 2013 at midnight Submit to [email protected] Discovery of new Mendelian disorders by Next Gen sequencing
Strategy Syndrome Full Genome Sequence Look for coding mutations Mutational load in a normal person Rare non-synonymous/splice site/insertions ~500 Rare, strong loss of function ~25
Genes with compound heterozygous mutations 1-3 stop stop homozygous stop
Glu -> Pro Compound heterozygous Find multiple people with the same syndrome Each person has ~25 mutations Look for mutations that affect the same gene Syndromes caused by mutations with a recessive phenotype
X X Affected 1 X X Affected
2 X X Affected 3 Dopa (3,4-dihydroxyphenylalanine)responsive
dystonia (DRD). Dystonia - involuntary muscle contractions that cause slow repetitive movements or abnormal postures. hereditary dystonia that gets worse late in the day. begins in childhood.
associated with mutations in genes encoding guanosine 5 -triphosphate -triphosphate (GTP), cyclohydrolase (GCH1), tyrosine hydroxylase (TH), and sepiapterin reductase (SPR). Bainbridge, M.N. et al. Whole-genome sequencing for optimized patient management. Sci. Transl. Med. 3, 87re3 (2011). Fig. 1 Metabolic pathways of neurotransmitter production. Bainbridge M N et al. Sci Transl Med 2011;3:87re3-87re3
Published by AAAS Clinical history fraternal twin pair. diagnosed with DRD at age 5. L-dopa was found to alleviate the clinical symptoms of dystonia in one twin. no identified deleterious variants in the TH or GCH1 genes.
Sequencing of the SPR gene was not available. high-throughput sequencing used to interrogate the whole genomes of the male and female twins. Mother Father X X
X X X X Affected
Affected Results Three genes found with rare compound heterozygous mutations. ZNF544 encodes a computationally predicted zinc finger protein with no known function or targets C2orf16. SPR encoding sepiapterin reductase. SPR mutations seen in two previous families with DRD.
Fig. 1 Metabolic pathways of neurotransmitter production. Bainbridge M N et al. Sci Transl Med 2011;3:87re3-87re3 Published by AAAS Results Gave serotonin precursor 5-hydroxytryptophan (5-HTP) to the twins. The male DRD patient reported improved focus in
school, as well as improved coordination in athletics. Further, the male showed reduced drooling and hand tremor. The female twin reported reduced frequency of laryngeal spasms, improved sleep and focus, and improved tolerance for exercise and was able to resume participation in sports after a 14-month absence. Miller Syndrome
Cupped ears coloboma of the lower eyelids, prominent nose, micrognathia absence of the fifth digits of the feet Ng, S.B. et al. Exome sequencing identifies the cause of a Mendelian disorder. Nat. Genet. 42, 3035 (2010).
Mother Father X X X X Affected
X Family 3 Family 2 Family 1 X
X X X X Affected 1A Affected
1B X X X X Affected
2 X X X X Affected
3 Non-synonymous and Rare (~450/person)
Two variants in the same gene (30/person) Same gene in 1A and 1B = 9 genes Same gene in 1A, 1B, 2 and 3 = DHODH dihydroorotate dehydrogenase Validate by sequencing the gene in 3 more cases. Kabuki Syndrome Ng, S.B. et al. Exome sequencing identifies MLL2 mutations as a cause of Kabuki syndrome. Nat. Genet. 42, 790793 (2010).
Kabuki syndrome distinctive facial appearance, cardiac anomalies, skeletal abnormalities, immunological defects and mild to moderate mental retardation. Six cases of parent-child transmission. Autosomal dominant disorder. Parent 1
Parent 2 X X Affected Strategy Look for rare, loss-of-function protein coding changes in
strongest patient Look for mutations in same gene in the second strongest patient, then third, then fourth, etc. After 4 patients, only one gene is common. MLL2 Retrospectively, see that MLL2 has suggestive mutations in 5 more patients. Ultimately, 9/10 patients had mutations in MLL2. For validation, found 26/43 patients had mutations in MLL2. 0/190 controls had mutations. Genomic structure and allelic spectrum of MLL2 mutations that cause Kabuki
syndrome The SET domain of MLL2 confers strong histone 3 lysine 4 methyltransferase activity and is important in the epigenetic control of active chromatin states. Schinzel-Giedon syndrome Severe mental retardation, distinctive facial features, multiple congenital
malformations (including skeletal abnormalities, genitourinary and renal malformations, and cardiac defects) and a higher-than-normal prevalence of tumors, notably neuroepithelial neoplasia. Hoischen, A. et al. De novo mutations of SETBP1 cause Schinzel-Giedion syndrome. Nat. Genet. 42, 483485 (2010). Mother Father
X Affected Strategy Look for rare, loss-of-function protein coding changes Only 1 gene shared in four patients SETB1. In all cases, mutations occurred de novo in patients and were absent from parents.
Validated in 8/9 additional patients. Gain-of-function effect or dominant-negative effect recap Dopa responsive disorder Knew the pathway and could guess which mutations were right Millers syndrome recessive mutations in DHODH
Kabuki syndrome autosomal dominant Shinzel Giedon syndrome spontaneous mutations www.mendelian.org www.mendelian.org Large scale public effort to identify Mendelian mutations UW/Yale/Hopkins/Baylor
Doctors send in samples Centers sequence families, find mutations Joint publication www.mendelian.org Sequencing 500 Mendelian families Either exome or wgs Overview of Next Gen
Sequencing results for disease Rare Syndromes: DRD, Millers etc. Not common diseases: Type 2 diabetes, cardiovascular disease Constrained to protein coding mutations. Mutations that disrupt expression not currently recognized. Much of Heritability is still missing.
Due to the culture of the country involved, the videos need to be made locally to reflect local culture and business practices. ... As a former QTAC employee, he understands the processes involved for assessing applications from non school leavers.
Real vs. Ideal Gas. Under what types of pressure do gases behave ideally? Under what type of temperatures do gases behave ideally? We originally defined ideal gases with as series of requirements. These included, no volume, elastic collisions, and they...
NORMAN AND MARGARET CORNE MEMORIAL AWARD FOR EXCELLENCE AND OUTSTANDING PROMISE IN RESEARCH DURING THE 1ST SUMMER OF THE BSC(MED) PROGRAM. Matthew Levesque. Project: Long-term outcomes of children with congenital diaphragmatic hernia: A population-level, virtual follow up of health, educational,...
7. Prior to World War I, what was the primary difference between the Egyptian and the Indian nationalist movements? A) In India, a single political party dominated the nationalist movement, but in Egypt, a variety of rival parties proliferated.
Junior Ladies of Charity "According to well known Catholic journalist John Allen Jr., by 2030 6.8 million additional Catholics will enter their retirement years, a stage of life when people are most likely to pray and go to church, and...
Can you name the slogan? Can you name the slogan? Can you name the slogan? Questions?? How can advertising affect a consumer's decision to purchase a product? What types of advertisements are out there? Are there any products you have...