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News and Updates


April 2008
GeneDx expands its menu for eye disorders: NOW gene testing available for Retinal Dystrophies

Retinal dystrophies are worldwide a major cause for genetic blindness. Included in this group is non-syndromic retinitis pigmentosa, which may be inherited as autosomal dominant, autosomal recessive, or X-linked trait. Retinitis pigmentosa is characterized by progressive degeneration of the retina leading to night blindness, decrease of the visual fields, tunnel vision, and eventually severe visual impairment. GeneDx offers sequential tiered testing for autosomal dominant retinitis pigmentosa (adRP). This panel will detect up to 57% of adRP and includes partial and/or full sequencing of seven genes: RHO, PRPH2 (RDS), IMPDH1, PRPF3, PRPF31, PRPF8 and RP1. The RHO gene has also been implicated in congenital stationary night blindness (CSNB) and retinitis punctata albescens (RPA). Mutations in the PRPH2 (RDS) gene also cause Cone-Rod Dystrophy (CRD) and autosomal dominant Macular Dystrophy (adMD). Testing of these genes is available for all these test indications.

In addition, GeneDx also offers genetic testing for choroideremia an X-linked recessive condition characterized by progressive degeneration of the photoreceptors, retinal pigment epithelium and choriocapillaris leading to blindness. Full sequencing is available for the CHM gene, which will detect up to 95% of males diagnosed with choroideremia.


March 2008
Check out our new Genome Analysis Tool!

GeneDx offers high-resolution, genome-wide oligonucleotide microarray analysis with our GenomeDx version 2.0. Our aCGH reports are detailed, comprehensive and discuss results down to the gene level. But if you want to know more about the genomic region or a specific gene identified by GenomeDx or any other microarray CGH test, use our
Genome Analysis Tool. This is an easy-to-use graphic portal, which provides access to the UCSC Genome Browser and live links to genes and genomic information, including OMIM and other online databases. Our Genome Analysis Tool will assist you in visualizing and researching genomic features of interest.


January 2008
Introducing GenomeDx Version 2.0: The next generation of chromosome analysis

As of January 1, 2008, GenomeDx has been improved with the introduction of version 2.0 to provide high-resolution genome-wide oligo aCGH analysis with increased probe density and technical sensitivity. It consists of a custom-designed, validated oligonucleotide-based microarray with 105,000 probes across the non-repetitive sequence of the genome to evaluate for known as well as novel genomic deletion and duplication syndromes.

Probes are now placed at 35 kb intervals across the genome, thus more than doubling the probe density compared to GenomeDx array version 1.0. An even higher (2-10 times) density of probes increases the sensitivity at over 120 targeted genomic regions of clinical significance. Based on this design, GenomeDx v.2.0 can identify regions of genomic gain and loss as small as 5-10 kb in the targeted regions and as small as 200 kb in other areas of the genome.


November 2007
Genetic testing for Rubinstein-Taybi syndrome (CREBBP gene) now available at GeneDx!

GeneDx now provides comprehensive testing of the CREBBP gene for patients with suspected Rubinstein-Taybi syndrome (RSTS). Mutation analysis of the CREBBP gene is offered in two tiers, which together include sequence analysis of the entire coding sequence as well as deletion analysis of the 5' and 3' portions and several internal exons of the gene. This combined approach is expected to identify >95% of deletions and small intragenic mutations within the gene, if they exist.


September 2007
GeneDx announces genetic testing for Cherubism, extending our test menu for pediatric dysmorphology syndromes. Cherubism is a descriptive name for the classic facial appearance of swollen cheeks and upwardly turning eyes (reminiscent of cherubs found in Renaissance art) secondary to abnormal bone degradation and remodeling of the jaw with multiple benign cysts. Affected individuals also can have dental abnormalities, and in rare cases, rib anomalies.

The jaw manifestations observed in Cherubism are often considered in the differential diagnosis of other syndromes including Noonan-like/Multiple giant-cell lesion syndrome (due to mutations in the PTPN11 gene), Central giant-cell granuloma, Fibrous dysplasia of the jaw, and Hyperparathyroidism. Full gene sequencing of the PTPN11 gene is available at GeneDx as well.

Mutations exclusive to exon 9 of the SH3BP2 gene have been identified in 80% of individuals clinically diagnosed with Cherubism. Cost-effective bi-directional sequencing of exon 9 is now offered for rapid diagnosis/exclusion of this syndrome.

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Testing for Hereditary Leiomyomatosis and Renal Cell Cancer (FH gene) is now available, enhancing our test menu for cancer-associated genetic syndromes.

  • Hereditary Leiomyomatosis and Renal Cell Cancer (HLRCC) is a tumor susceptibility syndrome with increased risks for cutaneous leiomyomas (smooth muscle tumors of the skin), uterine leiomyomas (smooth muscle tumors of the uterus or "uterine fibroids"), and renal cell cancer.

  • The renal cell cancer suggestive of HLRCC is often considered in the differential diagnosis of other cancer predisposition syndromes, notably Von Hippel-Lindau (VHL) and Birt-Hogg-Dubé (BHD). Additionally, the cutaneous leiomyomas associated with HLRCC share similarity to the cutaneous fibrofolliculomas observed in BHD. Genetic testing for all three disorders is available at GeneDx.
FH mutations have been identified in 76%-100% of individuals clinically diagnosed with HLRCC using a combination of full gene sequencing and gene deletion studies, both of which are available at GeneDx.


August 2007
GeneDx announces new testing of the COL4A5 gene in patients with the X-linked form of Alport syndrome (AS), which is characterized by progressive renal failure, sensorineural hearing loss and ocular findings, such as anterior lenticonus. Although Alport syndrome is genetically heterogeneous, up to 80% of patients were reported to have a mutation in the X-linked COL4A5 gene, while the remainder is expected to have mutations in the autosomal genes COL4A3 and COL4A4. Mutation analysis of the COL4A5 gene as offered by GeneDx will identify a disease-causing mutation, if it exists, in about 92% of affected males and over 90% of carrier females. The latter is important as most of the carrier females for Alport syndrome have microscopic hematuria and are at risk for developing renal failure later in life. Therefore, this new test is not only useful for confirming a clinical diagnosis and differentiating X-linked Alport syndrome from autosomal forms, it also allows identifying at-risk carrier females and developing a medical surveillance plan for them, determining the recurrence risks in a family, and offering the option of prenatal diagnosis in at-risk pregnancies.

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GeneDx expands its test menu to include full sequence analysis for the following metabolic disorders: Fatty Acid Oxidation Disorders: MCAD, VLCAD, SCAD, LCHAD and Mitochondrial Trifunctional Protein deficiencies Organic Acidurias: Methylmalonic aciduria and homocystinuria, cobalamin C type, methylmalonic acidemia (MUT, MMAA and MMAB) In addition sequence analysis of the PAH gene for Phenylketonuria is now available.

These sequencing tests are useful for confirming a biochemical diagnosis, for carrier testing and for prenatal diagnosis of at-risk pregnancies.


July, 2007
RAF1 gene sequence analysis added to Noonan Syndrome Test Panel! GeneDx announces further expanded, comprehensive, cost-saving testing strategies for Noonan syndrome.

On July 1, 2007, Nature Genetics published two papers (Abdur Rassaque et al; Pandit et al.) showing that mutation in yet another gene in the RAS-MAPK pathway is responsible for a subset of patients with Noonan Syndrome. RAF1 is the fourth gene thus far implicated in the disorder. Approximately 61% of individuals with a clinical diagnosis of Noonan syndrome (NS) are expected to have a mutation in 1 of the previously-identified genes, PTPN11, SOS1, and KRAS. In patients without mutation in these genes, between 8% and 17% have mutation in RAF1. Of particular clinical significance is that over 80% of patients with RAF1 mutation have Hypertrophic Cardiomyopathy (HCM), a finding that is seen in only 18% of Noonan patients generally. Based on these new findings, we have modified the testing tiers for our Noonan Syndrome molecular diagnosis. Sequential tiered testing remains the most cost-effective approach for your patient, and is predicted to identify a disease-associated mutation in 64% to 78% of NS patients. We have added RAF1 sequencing of three exons (where all mutations have thus far been identified) to the second tier of our test. Our Comprehensive Noonan syndrome panel is also still available, and provides simultaneous testing of the PTPN11, SOS1, RAF1,and KRAS genes for significantly shorter turn-around-times. This panel is predicted to detect >99% of existing mutations in these four genes. Alternatively, testing for PTPN11, SOS1, RAF1 and KRAS can be ordered individually for any patient who has previously had testing in one or more of the Noonan Syndrome genes.

GeneDx offers testing of PTPN11, SOS1, and RAF1 under a licensing agreement with Mt. Sinai Medical School.


June 27, 2007
GeneDx announces new testing for Niemann-Pick Disease, Types A (neurodegenerative form) and B (visceral form), which are rare allelic lipid storage disorders due to mutations in the SMPD1 gene and are characterized by accumulation of sphingomyelin in reticulo-endothelial and other cell types in the body. Niemann-Pick Disease, Type A is panethnic but especially common in the Ashkenazi Jewish population. It is more severe and progressive than Type B because the SMPD1 gene product, acid sphingomyelinase, is completely abolished or enzyme activity is < 5%. The disorder then results in rapid neurological degeneration, hypotonia, rigidity, and mental retardation, with fatal outcome within approximately 3 years after onset. Niemann-Pick Type B patients remain mostly free ofneurological manifestations and typically live into adulthood. In Niemann-Pick Disease Type B, the defective enzyme retains residual catalytic activity, thus resulting in the milder phenotype.

Niemann-Pick Disease Types A and B are autosomal recessive disorders with increased carrier frequencies within certain populations, such as the Ashkenazi Jews and others. The identification of mutations in an affected individual allows the diagnosis of Niemman-Pick Type A or B to be definitively made, which makes it possible for other at risk family members to undergo carrier testing and prenatal diagnosis.


June 16, 2007
The CASP8 and CASP10 genes are now available for testing in patients with Autoimmune Lymphoproliferative Syndrome (ALPS) who are negative for TNFRSF6 (FAS) mutations. CASP8 and CASP10 together define the category ALPS Type II, thought to represent about 10% of ALPS patients. These tests can be added after TNFRSF6 testing without sending an additional specimen.


June 14, 2007
GeneDx announces testing for Feingold syndrome (MYCN gene), a multiple congenital anomaly syndrome characterized by microcephaly, digital abnormalities, and esophageal/duodenal atresia. Many features observed in Feingold syndrome overlap with the VATER and VACTERL associations, especially in patients with esophageal/duodenal atresia.

Feingold syndrome is an autosomal dominant disorder and sporadic cases due to de novo mutations occur in ~50% of patients. Test sensitivity is approximately 65%. Mutation analysis of the MYCN gene will be useful in differentiating the diagnosis of Feingold syndrome from other syndromes with overlapping phenotypes, for determining the recurrence risks, and for prenatal diagnosis in at-risk pregnancies.


June 12, 2007
Testing for Duane-Radial Ray syndrome (SALL4 gene) is now available, expanding our menu for genetic syndromes with congenital limb anomalies, also including Holt-Oram syndrome and Townes-Brocks syndrome.
  • Duane-Radial Ray syndrome (DRRS) is characterized by the congenital Duane eye movement disorder and radial ray limb malformations such as triphalangeal thumbs, preaxial polydactyly, hypoplasia/aplasia of the thumbs, hypoplasia/aplasia of the radii, and shortening and radial deviation of the forearms.
  • Acro-Renal-Ocular syndrome (AROS), an allelic condition to DRRS, presents with radial ray malformations and Duane anomaly, along with other features such as ocular coloboma and renal abnormalities.
  • The limb and other anomalies suggestive of DRRS/AROS are often considered in the differential diagnosis of Holt-Oram syndrome (HOS) and Townes-Brocks syndrome (TBS). Genetic testing for all three disorders is available at GeneDx. The test sensitivity is high. According to two recent reports, mutations can be identified in the vast majority of patients with DRRS/AROS using a combination of full gene sequencing and gene copy number analysis, both of these tests are offered by GeneDx.



April 2007
We've Grown- Both Inside & Out!

We've added 7,000 sq ft. to our GeneDx home this April, for a total of ~15,000 sq ft. With our new expansion we have additional space for our new genetic counselors, data analysis, and our array-CGH (GenomeDX) services. From 7 to 47 employees (and growing!) in a 5 year span, we look forward to our expanding team and services.

GenomeDx: Whole Genome Analysis using Oligonucleotide Microarray

This NEW diagnostic service specifically tests the entire genome for regions of genomic gains and losses. Such changes in DNA dosage, ie., genomic deletions, duplications and amplifications, may be associated with a multitude of pediatric and adult genetic disorders. The technology is also known as Chromosomal Microarray Analysis (CMA) or oligo array Comparative Genomic Hybridization (oligo aCGH). For detailed information on this service, including technical design, test method, sensitivity, limitations, and relevant literature, please read our GenomeDx Information Sheet including prices and CPT codes.



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