Case Report: Whole-Exome Sequencing of Hypothalamic Hamartoma From an Infant With Pallister-Hall Syndrome Revealed Novel de novo Mutation in the GLI3

Bardet-Biedl Syndrome Presenting With Bifid Epiglottis: A Case Report and Review of Literature

Bifid epiglottis is a rare congenital laryngeal anomaly that is most commonly a syndromic rather than an isolated entity. It has been associated with specific syndromes, such as Pallister-Hall syndrome, Bardet-Biedl syndrome, and other related syndromes. Bardet-Biedl syndrome is a rare autosomal-recessive disorder characterized by hand and/or feet polydactyly, obesity, short stature, mental retardation, renal anomalies, and genital anomaly. Here we report a case involving a 25-year-old Saudi male patient who presented with hoarseness of voice since birth with no diurnal or diet association or other associated symptoms. On examination, he was noted to have craniofacial dysmorphism and polydactyly of the right hand and left foot. Fiberoptic nasopharyngolaryngoscopy (NPLS) revealed a laryngeal pedunculated rounded glottic mass and subglottic bulging with expiration and involuting with inspiration along with an abnormal-looking epiglottis having a separate cartilaginous framework with space in-between and bilateral mobile vocal cords. Computed tomography (CT) showed the vocal cord mass and a bifid epiglottis. Other investigations and labs were within normal range. The patient underwent vocal cord mass excision and soft tissue histopathology revealed a benign growth. On follow-up, the patient showed clinical improvement. In conclusion, this is a rare case of bifid epiglottis associated with Bardet-Biedl syndrome, which serves to highlight the significance of such anomalies in any syndromic patient presenting with airway symptoms. Our aim is to add more cases to the literature and to consider it as a differential diagnosis.

Case Report: Prenatal Diagnosis of Postaxial Polydactyly With Bi-Allelic Variants in Smoothened (SMO)

Postaxial polydactyly is a common congenital malformation which involves complex genetic factors. This retrospective study analyzed the cytogenetic and molecular results of a Chinese fetus diagnosed with postaxial polydactyly of all four limbs. Fetal karyotyping and chromosomal microarray analysis (CMA) did not find any abnormality while trio whole-exome sequencing (trio-WES) identified bi-allelic variants in smoothened (SMO) and (NM_005631.5: c.1219C > G, NP_005622.1: p. Pro407Ala, and NM_005631.5: c.1619C > T, NP_005622.1: p. Ala540Val). Sanger sequencing validated these variants. The mutations are highly conserved across multiple species. In-depth bioinformatics analysis and familial co-segregation implied the compound heterozygous variants as the likely cause of postaxial polydactyly in this fetus. Our findings provided the basis for genetic counseling and will contribute to a better understanding of the complex genetic mechanism that underlies postaxial polydactyly.