12q14 microdeletion syndrome: A family with short stature and Silver-Russell syndrome (SRS)-like phenotype and review of the literature

We report here on the first family with short stature and Silver-Russell-like phenotype due to a microdeletion in 12q14.3. The Netchine-Harbison clinical scoring system was used for the clinical diagnosis of Silver-Russell syndrome (SRS). The three affected first-degree relatives (index patient, mother and brother) presented with prenatal and postnatal growth retardation, feeding difficulties, a prominent forehead and a failure to thrive, but did not show relative macrocephaly. In addition, our index patient showed dysmorphic facial features, periodically increased sweating, and scoliosis. Learning problems and cardiac arrhythmia presented as additional features of her brother. Using high-resolution array-CGH, heterozygosity for a 1.67?Mb deletion in 12q14.3 was detected in the index patient. The heterozygous loss was confirmed by MLPA in the index patient and the other two affected family members. The deletion includes the genes HMGA2, LLPH, TMBIM4, IRAK3, HELB, GRIP1, and the pseudogene RPSAP52. We conclude from these results and from the data of other patients reported in the literature that haploinsufficiency of HMGA2 leads to the short stature in this family.     

FOXA2 gene mutation in a patient with congenital complex pituitary hormone deficiency

We report a patient with congenital complex pituitary hormone deficiency (CPHD) with intestinal malrotation and anal atresia. We identified a de novo heterozygous mutation, c.664T > G (p.Cys222Gly), in the FOXA2 gene in this individual. This missense mutation had the potential to affect the DNA binding properties of the FOXA2 protein based on a protein structure prediction. Since a CPHD patient with another missense mutation and one other case with an entire gene deletion have also been reported, we speculated that a haploinsufficiency of the FOXA2 gene might be a genetic etiology for this disorder. Phenotypic similarities and differences among these three cases are also discussed.     

Exome sequencing identified a de novo mutation of PURA gene in a patient with familial Xp22.31 microduplication

The clinical significance of Xp22.31 microduplication is controversial as it is reported in subjects with developmental delay (DD), their unaffected relatives and unrelated controls. We performed multifaceted studies in a family of a boy with hypotonia, dysmorphic features and DD who carried a 600?Kb Xp22.31 microduplication (7515787-8123310bp, hg19) containing two genes, VCX and PNPLA4. The duplication was transmitted from his cognitively normal maternal grandfather.We found no evidence of the duplication causing the proband's DD and congenital anomalies based on unaltered expression of PNPLA4 in the proband and his mother in comparison to controls and preferential activation of the paternal chromosome X with Xp22.31 duplication in proband's mother. However, a de novo, previously reported deleterious, missense mutation in Pur-alpha gene (PURA) (5q31.2), with a role in neuronal differentiation was detected in the proband by exome sequencing.We propose that the variability in the phenotype in carriers of Xp22.31 microduplication can be due to a second and more deleterious genetic mutation in more severely affected carriers. Widespread use of whole genome next generation sequencing in families with Xp22.31 CNV could help identify such cases.