Borjeson-Forssman-Lehmann Syndrome: PHF6 Gene Deletion/Duplication

Condition Description

Borjeson-Forssman-Lehmannsyndrome (BFLS) is an X-linked intellectual disability syndrome. Characteristics ofthis syndrome include severe mental defect, epilepsy, hypogonadism,hypometabolism, marked obesity, swelling of subcutaneous tissue of face, narrowpalpebral fissure, and large but not deformed ears. Affected individuals mayhave a characteristic facial appearance consisting of prominent superciliaryridges, deep-set eyes, ptosis, and large ears.

Thephenotype of BFLS seems to evolve with age. Generally, babies with BFLS arefloppy, with failure to thrive, big ears, and small external genitalia. Inchildhood, boys may display learning problems and moderate short stature, withemerging truncal obesity and gynecomastia. Head circumference is usuallynormal, and macrocephaly may be seen. Big ears and small genitalia remain. Thetoes are short and fingers tapered and malleable. In late adolescence and adultlife, the classically described heavy facial appearance emerges.

Someheterozygous females display milder clinical features such as tapering fingersand shortened toes. Significant learning problems have been reported inapproximately 20% of female carriers, and skewed X inactivation inapproximately 95%. Carrier females have also been reported with epilepsy,characteristic facial feratures, obesity, amenorrhea, and hypothyroidism.

Mutationsin the PHF6 gene (Xq26.3) have beenassociated with BFLS.

Click here for the OMIM summary on this condition.

Genes (1)

Your search may have returned a result for a gene alias. Click here for a full list of genes and their aliases.

Indications

This test is indicated for:

  • Confirmation of a clinical/biochemical diagnosis of Borjeson-Forssman-Lehmann syndrome in individuals who have tested negative for sequence analysis
  • Carrier testing in adult females with a family history of Borjeson-Forssman-Lehmann syndrome who have tested negative for sequence analysis

Methodology

DNA isolated from peripheral blood is hybridized to a CGH array to detect deletions and duplications. The targeted CGH array has overlapping probes which cover the entire genomic region.

Detection

Detection is limited to duplications and deletions. The CGH array will not detect point or intronic mutations.Results of molecular analysis must be interpreted in the context of the patient's clinical and/or biochemical phenotype.

Specimen Requirements

When sample fails to meet the acceptable criteria, please call 470.378.2200 and ask to speak with a laboratory genetic counselor (eglgc@egl-eurofins.com).
Submit only 1 of the following specimen types
Whole Blood (EDTA)
WBP

Requirements
EDTA (Purple Top)
Infants and Young Children (<2 years of age): 2-3 ml
Children > 2 years of age to 10 years old: 3-5 ml
Older Children & Adults: 5-10 ml
Autopsy: 2-3 ml unclotted cord or cardiac blood
Collection and Shipping
Ship sample at room temperature for receipt at EGL within 24 hours of collection. Do not refrigerate or freeze.
DNA, Isolated
DNA

Requirements
Microtainer
3µg
Isolation using the Perkin Elmer™Chemagen™ Chemagen™ Automated Extraction method or Qiagen™ Puregene kit for DNA extraction is recommended.
Collection and Shipping
Refrigerate until time of shipment in 100 ng/µL in TE buffer. Ship sample at room temperature with overnight delivery.

Special Instructions

Submit copies of diagnostic biochemical test results with the sample, if appropriate. Contact the laboratory if further information is needed.

Sequence analysis is required before deletion/duplication analysis by targeted CGH array. If sequencing is performed outside of EGL Genetics, please submit a copy of the sequencing report with the test requisition.

  • Sequencing analysis of the PHF6 gene is available (YH) and is required before deletion/duplication analysis.
  • ACGH array-based test for deletion/duplication analysis of 64 differentX-linked intellectual disability genes is available (OL).
  • Prenataltesting is available to adult females who are confirmed carriers ofmutations. Please contact the laboratory genetic counselor to discussappropriate testing prior to collecting a prenatal specimen.

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