J Bone Metab.  2017 Nov;24(4):257-261. 10.11005/jbm.2017.24.4.257.

X-linked Hypophosphatemic Rickets, del(2)(q37.1;q37.3) Deletion Syndrome and Mosaic Turner Syndrome, mos 45,X/46,X, del(2)(q37.1;q37.3) in a 3-year-old Female

• Vidmar AP
• Miyazaki B
• Sanchez-Lara PA
• Pitukcheewanont P

• KMID: 2397560
• DOI: http://doi.org/10.11005/jbm.2017.24.4.257

Abstract

There are currently no published cases that report concomitant Turner syndrome (TS), 2q37 deletion syndrome and X-linked hypophosphatemic rickets (XLH). Interestingly, since the clinical phenotypes of TS and 2q37 deletion syndrome overlap, the correct diagnosis may be missed without a standardized approach to genetic testing consisting of both karyotype and microarray. Both chromosome anomalies have been associated with short stature and a variety of skeletal abnormalities however to date no reports have associated these syndromes in association with a phosphate regulating endopeptidase homolog, X-linked (PHEX) gene deletion resulting in XLH. We report a 3-year-old female with 3 concurrent genetic disorders including a 9.98 Mb terminal deletion of chromosome 2: del(2)(q37.1;q37.3), XLH secondary to a small microdeletion of part of the PHEX gene, and mosaic TS (mos 45,X[32]/46,X[18]). This is the first case report of a patient with 2q37 deletion syndrome and mosaic TS (mos 45,X[32]/46,X[18]) found to have XLH secondary to an interstitial constitutional PHEX gene deletion. Her severe phenotype and multiple genotypic findings reinforce the importance of thorough genetic testing in the setting of complicated phenotypic presentations.

Keyword

Bone diseases; Microarray analysis; Rickets hypophosphatemic; Turner syndrome

MeSH Terms

Bone Diseases
Child, Preschool*
Chromosomes, Human, Pair 2
Diagnosis
Familial Hypophosphatemic Rickets*
Female*
Gene Deletion
Genetic Testing
Humans
Karyotype
Microarray Analysis
Phenotype
PHEX Phosphate Regulating Neutral Endopeptidase
Turner Syndrome*
PHEX Phosphate Regulating Neutral Endopeptidase

Figure

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  Fig. 1 Skeletal survey obtained at the time of diagnosis. Significant for severe diffuse osteopenia, with diffuse metaphyseal irregularities and flaring with multiple fractures.

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