14q13 distal microdeletion encompassing NKX2-1 and PAX9: Patient report and refinement of the associated phenotype.

Chromosome 14q11-q22 deletion syndrome (OMIM 613457) is a rare genomic disorder whose associated phenotype is heterogeneous, depending on the size, and, mostly, on the deleted region. We report the clinical and molecular characterization of a female newborn, whose phenotype was characterized by poor growth, dysmorphic facial features, subclinical hypothyroidism, and mild reduction of CD3CD8 Lymphocytes with increased CD4/CD8 ratio. By array-CGH, we identified a 4.08 de novo interstitial deletion of the 14q13.2q21.1 region, which includes 16 OMIM genes.Our patient phenotype is compared with other published cases, for a better classification of the 14q11-q22 deletion syndrome. We demonstrated that the 14q13.2q21.1 deletion, which encompasses NKX2-1, but not FOXG1 gene and HPE8 region, identifies a well defined, more benign, microdeletion syndrome. This report confirms that an early identification with accurate characterization of the genomic disorders is of great relevance, enabling proper genetic counseling of the reproductive risk, as well as disease prognosis, and patient management. © 2016 Wiley Periodicals, Inc.

14q12q13.2 microdeletion syndrome: Clinical characterization of a new patient, review of the literature, and further evidence of a candidate region for CNS anomalies.

BACKGROUND: Chromosome 14q11-q22 deletion syndrome (OMIM 613457) is a rare contiguous gene syndrome. Two regions of overlap (RO) of the 14q12q21.1 deletion have been identified: a proximal region (RO1), including FOXG1(*164874), NKX2-1(*600635), and PAX9(*167416) and a distal region (RO2), including NKX2-1 and PAX9. We report a 6-year-old boy with mild dysmorphic facial features, global developmental delay, and hypoplasia of the corpus callosum. METHODS AND RESULTS: Array-CGH analysis revealed a 14q12q13.2 microdeletion. We compared the phenotype of our patient with previously published cases in order to establish a genotype-phenotype correlation. CONCLUSION: The study hypothesizes the presence of a new RO, not including the previously reported candidate genes, and attempt to define the associated molecular and psychomotor/neurobehavioral phenotype. This region encompasses the distal breakpoint of RO1 and the proximal breakpoint of RO2, and seems to be associated with intellectual disability (ID), hypotonia, epilepsy, and corpus callosum abnormalities. Although more cases are needed, we speculated on SNX6(*606098) and BAZ1A(*605680) as potential candidate genes associated with the corpus callosum abnormalities.