Reanalysis of a novel variant in the IGF1R gene in a family with variable prenatal and postnatal growth retardation and dysmorphic features: benefits and feasibility of IUSM-URDC (Undiagnosed Rare Disease Clinic) program.
Cold Spring Harb Mol Case Stud
; 8(2)2022 02.
Article
en En
| MEDLINE
| ID: mdl-35091507
ABSTRACT
IGF1R-related disorders are associated with intrauterine growth restriction (IUGR), postnatal growth failure, short stature, microcephaly, developmental delay, and dysmorphic facial features. We report a patient who presented to medical genetics at 7 mo of age with a history of IUGR, poor feeding, mild developmental delays, microcephaly, and dysmorphic facial features. Whole-exome sequencing revealed a novel c.1464T > G p.(Cys488Trp) variant in the IGF1R gene, initially classified as a variation of uncertain significance (VUS). We enrolled the patient in the URDC (Undiagnosed Rare Disease Clinic) and performed additional studies including deep phenotyping and familial segregation analysis, which demonstrated that the patient's IGF1R VUS was present in phenotypically similar family members. Furthermore, biochemical testing revealed an elevated serum IGF-1 level consistent with abnormal IGF-1 receptor function. Workup resulted in the patient's variant being upgraded from a VUS to likely pathogenic. Our report expands the variant and phenotypic spectrum of IGF1R-related disorders and illustrates benefits and feasibility of reassessing a VUS beyond the initial molecular diagnosis by deep phenotyping, 3D modeling, additional biochemical testing, and familial segregation studies through the URDC, a multidisciplinary clinical program whose major goal is to end the diagnostic odyssey in patients with rare diseases.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Enfermedades Raras
/
Microcefalia
Tipo de estudio:
Prognostic_studies
Aspecto:
Implementation_research
Límite:
Female
/
Humans
/
Pregnancy
Idioma:
En
Revista:
Cold Spring Harb Mol Case Stud
Año:
2022
Tipo del documento:
Article
País de afiliación:
Estados Unidos