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Phelan–McDermid syndrome (PMS) is a rare, heterogeneous, and complex neurodevelopmental disorder. It is generally caused by a heterozygous microdeletion of contiguous genes located in the distal portion of the long arm of chromosome 22, including the SHANK3 gene. Sequence variants of SHANK3, including frameshift, nonsense mutations, small indels and splice site mutations also result in PMS. Furthermore, haploinsufficiency in SHANK3 has been suggested as the main cause of PMS. SHANK3 is also associated with intellectual disability, autism spectrum disorder and schizophrenia. The phenotype of PMS is variable, and lacks a distinctive phenotypic characteristic, so the clinical diagnosis should be confirmed by genetic analysis. PMS is a multi-system disorder, and clinical care must encompass various specialties and therapists. The role of risperidone, intranasal insulin, insulin growth factor 1, and oxytocin as potential therapeutic options in PMS will be discussed in this review. The diagnosis of PMS is important to provide an appropriate clinical evaluation, treatment, and genetic counseling.

Spondylometaphyseal dysplasia Algerian type (MIM no.: 184253) is an uncommon autosomal dominant skeletal dysplasia caused by heterozygous mutations in the COL2A1 gene (MIM no.: 120140). In this case based review, we reported a 5-year-old boy with short stature, severe dorsolumbar scoliosis, lumbar hyperlordosis, short trunk, and severe genu valgum. Radiological examination showed platyspondyly, irregular metaphyseal radiolucencies intermingled with radiodensities, and corner fractures. The patient has a c.3275G > A; p.Gly1092Asp mutation in exon 47 of the COL2A1 gene and a variant of unknown significance in c.1366–13C > A in intron 21. This latter sequence variant could partially or completely disrupt the natural splice acceptor site of intron 21/exon 22 in the COL2A1 gene leading to a potential modification of the phenotypic severity.

Keratitis-ichthyosis-deafness (KID syndrome) is a syndromes ichthyoses that is clinically and genetically heterogeneous requiring early and long-term multidisciplinary monitoring of affected individuals. A review of the clinical, etiopathogenic and therapeutic aspects is presented of this rare congenital ectodermal disorder.