Microdeletions of 17q12 including the hepatocyte nuclear factor 1 beta (HNF1B) gene, as well as point mutations
of this gene, are associated with the Renal Cysts and Diabetes syndrome (RCAD, OMIM 137920) and genitourinary
alterations. Also, microdeletions encompassing HNF1B were identified as a cause of Mayer\u2013Rokitansky\u2013
K\ufcster\u2013Hauser Syndrome (MRKH, OMIM277000) in females and, recently,were associatedwith intellectual disability,
autistic features, cerebral anomaly and facial dysmorphisms.
In this report, we describe a boywith a deletion in 17q12 region detected by SNP array, encompassing the HNF1B
gene, that showed dysmorphic features, intellectual disability (ID), serious speech delay and autistic features. In
addition, obesity was observed. In order to study the parental origin of the rearrangement, we analyzed selected
SNPs in the deleted area in the patient and his parents, showing Mendelian incompatibilities suggesting a de
novo deletion on the chromosome of maternal origin.
Our case confirms the incomplete penetrance and variable expressivity of this deletion, its complex clinical variability,
and strengthens the evidence that ID and stereotyped behaviors may be part of the phenotypic spectrum
characterizing the affected patients. Also, it is useful to further delineate the phenotypes associated to the deletion
being the first case in which obesity has been documented. We present a genotype\u2013phenotype correlation
discussing the possible role of some genes, encompassed by the deletion, in the etiology of the observed
phenotypes
