Alpha-mannosidosis Serum Oligosaccharide Analysis

Patients with alpha-mannosidosis cannot break down various oligosaccharides that contain a terminal mannose residue, which results in their accumulation in body tissues.  This assay measures five different free oligosaccharides in serum or plasma that accumulate in patients with alpha-mannosidosis and can be used for both the diagnosis and treatment monitoring of patients with this disorder.  GlcNAc(Man)2 is measured quantitatively and GlcNAc(Man)3, GlcNAc(Man)4, GlcNAc(Man)5 and GlcNAc(Man)6 are measured semi-quantitatively.

Prenatal Exome Sequencing-XL

Prenatal exome sequencing-XL (PES-XL) is available for patients with abnormal findings on ultrasound. This is a phenotype-driven analysis where only pathogenic and likely pathogenic variants related to the reported clinical features will be included in the prenatal report.

PES-XL can be requested as a duo (maternal and fetal sample) or as a trio (maternal, paternal, and fetal sample). Maternal Cell Contamination (MCC) is required for this test. performing a trio, a separate family studies form and consent is required.

Reanalysis may be requested at no additional charge after the baby is born. Any new medical information should be reported to the lab upon request for reanalysis. A new consent form will be required for reanalysis. Any changes suspected of causing the concerns identified during pregnancy will require a postnatal sample for confirmation.

 

 

 

Whole Exome Sequencing-XL

Whole exome sequencing–XL (WES-XL) is a comprehensive, phenotype-driven exome analysis using the patient’s genomic data. Identified variants may be confirmed via Sanger sequencing or qPCR if needed as determined by the specific variant called. The standard WES-XL includes a trio analysis (patient plus parents). Samples from can be submitted in place of a parental specimen or in addition to parental samples. (Please note that an additional cost may incur for submitting more than 2 family members in addition to the proband.) Singleton and duos will also be accepted if appropriate family members samples are not available. A separate consent and family studies form must be completed for each familial sample submitted in addition to the patient. Please contact the lab prior to sending a sibling sample.

Secondary findings will only be reported for the patient initially, and only mutations or variants that are expected to harm the function of the gene will be reported. Only SNV analysis will be performed for secondary findings. The patient and/or patient’s guardian has the option to receive or not to receive the information about the patient’s changes that are considered secondary findings. If the lab does not have clear consent to report secondary findings, this will not be included in the final report. If a secondary finding is identified, parents may then elect to have the finding confirmed at no additional charge.

Cytogenomic Microarray

The Cytogenomic Microarray provides genome-wide detection of copy number gains and losses. In addition to detection of copy number variations (CNVs), this SNP array also allows for the analysis of loss of heterozygosity (LOH) which can be useful in identifying uniparental disomy (UPD) as well as autozygosity (identity by descent).

Mitochondrial DNA Variant Panel

This targeted panel include 96 mitochondrial DNA variants with known phenotypes. Below is a list of variants which are considered in the analysis. The variant “m.7445A>G” is located at the boundary of two genes, MT-CO1 and MT-TS1, and is commonly considered as two variants.

Krabbe Disease: Psychosine Monitoring

Psychosine, also known as galactosylsphingosine, is a substrate of the galactocerebrosidase (GALC) enzyme that is deficient in Krabbe disease. Thus, psychosine is used as a biomarker for patients with Krabbe disease, both for diagnosis and for treatment monitoring. Psychosine can also be elevated in atypical Krabbe disease due to Saposin A deficiency due do variants in the PSAP gene.

GNAS Methylation-Specific MLPA

GNAS Methylation-Specific MLPA is a molecular test used to detect copy number variants and methylation abnormalities within the GNAS complex locus on chromosome 20q13.32.

Lucy's Story

When our daughter Lucy had a metabolic crisis at 7 days old, we were shocked and devastated to find out that she was born with a rare genetic disorder (MSUD). Her newborn screening results did not make it back in time to prevent the crisis, and no one at our local hospital was familiar with the disease. They did not know how to treat her. Calls were made to Greenwood Genetic Center to confirm her diagnosis and guide her care. Dr. Champaigne and Ami...

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