[Clinical phenotype and genetic analysis of a child featuring short stature and multiple skeletal dysplasia].

OBJECTIVE: To analyze the clinical phenotype and genetic basis for a child featuring familial short stature. METHODS: A child who was admitted to Huzhou Maternal and Child Health Care Hospital on October 7, 2021 for growth retardation and pectus carinatum was selected as the study subject. Physical exam and medical imaging was performed. The child was subjected to whole exome sequencing, and candidate variants were verified by Sanger sequencing and bioinformatic analysis. RESULTS: The child, a 1-year-old male, had manifested with slightly short stature (Z = -2.03), midfacial dysplasia, and multiple skeletal dysplasia such as pectus carinatum, irregular vertebral morphology, and defect of lumbar anterior bones. His mother, maternal grandmother and great-maternal grandfather also had short stature. WES revealed that the child has harbored a heterozygous c.2858dupA (p.Asp953GlufsTer476) frameshifting variant of the ACAN gene, which was inherited from his mother. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the c.2858dup (p.Sp953Glufster476) variant was classified as likely pathogenic (PVS1+PM2_Supporting). The patient has shown marked improved height after receiving 11 months of treatment with human recombinant growth hormone (supplemental dose) starting from 20 months of age. CONCLUSION: The ACAN: c.2858dup (p.Asp953GlufsTer476) variant probably underlay the pathogenesis of short stature in this child.

Mayer-Rokitansky-Küster-Hauser syndrome with idiopathic central precocious puberty: a case report.

Background: Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome is mainly characterized by congenital aplasia of the uterus and the upper two-thirds of the vagina in females with normal secondary sex characteristics and female karyotype (46,XX). MRKH syndrome is typically diagnosed due to primary amenorrhea in adolescence and is very difficult to diagnose in childhood. MRKH syndrome combined with central precocious puberty (CPP) is extremely rare. In this article, we report a case of MRKH syndrome with idiopathic CPP (ICPP). Case Description: A 7-year-old girl was presented with development of bilateral breasts for 1 year and relatively low body height. Based on her age, clinical signs, and laboratory findings, she was initially diagnosed with ICPP and treated with sustained-release gonadotropin-releasing hormone analog (GnRHa) therapy, and recombinant human growth hormone (rhGH) therapy from the 6th month onwards. During the follow-up, ultrasound and magnetic resonance imaging showed no uterus or uterine neck, an unclear vaginal structure, and normal ovaries. Her chromosome karyotype was 46,XX. A pediatric gynecological examination showed colpatresia. She was finally diagnosed with MRKH syndrome combined with CPP. After the GnRHa and rhGH treatment, her height became normal compared to her peers, and her bone age development was delayed. Conclusions: The present case suggests the possibility of concomitant CPP in patients with MRKH syndrome. The gonads and sexual organs of children with precocious puberty should be carefully monitored and assessed to exclude any sexual organ disorders.

[Genetic analysis of a rare case of Pitt-Hopkins syndrome due to partial deletion of TCF4 gene].

OBJECTIVE: To explore the genetic basis for a child featuring delayed intellectual development. METHODS: The child and his parents were subjected to conventional G-banding karyotyping and single nucleotide polymorphism array (SNP-array) analysis. Suspected copy number variations (CNVs) were verified in both parents. RESULTS: No karyotypic abnormality was found with the child and his parents. SNP-array results for both parents were normal. The child was found to harbor a de novo 172 kb deletion at 18q21.2 with a physical position of 52 957 042-53 129 237. The deletion only involved one OMIM gene, namely TCF4, resulting in removal of its exons 6 to 8. CONCLUSION: The SNP-array assay has facilitated with the diagnosis of this child. Deletion of 18q21.2 region probably accounts for the Pitt-Hopkins syndrome (PTHS) in this patient.

[Identification of a c.1A>G initial codon variation of ARX gene in a child with severe mental retardation].

OBJECTIVE: To explore the genetic basis for a child featuring severe mental retardation. METHODS: The child was subjected to target region capture and next generation sequencing. Suspected variants were verified by Sanger sequencing. RESULTS: The child was found to harbor a hemizygous c.1A>G (pMet1?) variation of the ARX gene, for which his mother was a heterozygous carrier. The mutation was unreported previously and was predicted to be "probably pathogenic" by bioinformatic analysis. CONCLUSION: The c.1A>G (pMet1?) variant of the ARX gene may underlie the occurrence of severe mental retardation in this child.