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Objective To observe the changes of corresponding proteins and function based on known clinical dihydroorotate dehydrogenase(DHODH) mutation types,i.e.,G202A,R346W and R135C in the patients with Miller syndrome.Methods HeLacell lines stably expressing Miller syndrome pathogenic mutation types G202A,R346W and R135C were established.Then the mitochondrial localization function,protein stability and enzyme activity of corresponding proteins were studied by the immunohistochemistry and mitochondrial layered positioning.Results The mitochondrial localization function of 3 kinds of DHODH mutation were not affected,which existed in the mitochondrial inner membrane after expression.The mutant G202A and R346W protein stability was reduced;the mutant R135C protein was stable,but base induced enzyme activity injury caused the deficiency of corresponding enzymatic activity.Conclusion The DHODH function injury may be related with the symptoms in Miller syndrome.
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Objective To observe the changes of the skeletal development related cells after dihydroorotate dehydrogenase (DHODH) deficiency.Methods The DHODH expression in MC3T3-E1 cells derived from mouse calvaria osteoblast precursor cells was inhibited by specific small interfering RNAs (siRNAs),and cell proliferation,ATP production and expression levels of bone-related genes were investigated in these cells.Results After reducing the DHODH expression by using specific siRNAs,cell proliferation was inhibited and cell cycle was arrested at G1/S stage.In addition,the ATP production was reduced in whole cells,especially in mitochondria.Furthermore,the expression levels of Runt-related transcription factor 2 (Runx2) and osteocalcin (Ocn) mRNAs in the DHODH inhibition group were decreased compared with the control group.Conclusion Inhibiting DHODH protein affects the differentiation and maturation of osteoblasts.The mitochondrial dysfunction in osteoblasts may be one of causes leading to the abnormal bone formation in Miller syndrome.
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Introducción: El síndrome 3M combina retardo de crecimiento prenatal y postnatal severo, dismorfias faciales (semeja facies "melancólica") y anomalías radiológicas. Es una enfermedad infrecuente de la que hasta el momento se han descrito alrededor de 200 casos. "3M" se refiere a las iniciales de los tres autores que describieron este síndrome. Los rasgos faciales característicos son: cabeza relativamente grande, dolicocefalia, abombamiento frontal, cara triangular, mentón prominente, nariz antevertida, labios gruesos, cejas gruesas, surco nasolabial largo e hipoplasia de tercio medio de cara. Los hallazgos radiológicos, que van apareciendo con la edad son costillas y huesos largos finos y delgados, y cuerpos vertebrales altos. El síndrome 3M se transmite como un rasgo autosómico recesivo y es genéticamente heterogéneo. Objetivo: Descripción del caso clínico de una nina actualmente de 10 años de edad en el que se confirmó este síndrome. Caso clínico: Nina referida a Genética a los 15 meses de vida, por talla baja severa, dismorfias y malformaciones. Su seguimiento clínico y radiológico permitió plantear y confirmar este diagnóstico. Conclusión: En ocasiones sólo el seguimiento longitudinal de pacientes con talla baja severa permite que se evidencien alteraciones sugerentes de un diagnóstico específico. La certificación del diagnóstico favorece un adecuado manejo clínico y consejería genética a los padres.
Introduction: 3M syndrome combines severe prenatal and postnatal growth delay, facial dysmorphism (resembles melancholy facies) and radiological abnormalities. It is a rare disease with 200 cases reported so far. "3M" refers to the initials of the three authors who first described this syndrome. The characteristic facial features are: relatively large head, dolichocephaly, frontal bossing, a triangular face, pointed chin, upturned nose, full lips, full eyebrows, long philtrum and hypoplastic midface. radiological findings which appear with age, include slender long bones and ribs and tall vertebral bodies. 3M syndrome is transmitted as an autosomal recessive trait and is genetically heterogeneous. Objective: Report the clinical case of a girl, now 10 years of age, diagnosed with the syndrome. Case report: An infant girl, 15 months old, was referred to Genetics Clinic due to severe short stature, dysmorphic features and malformations. Her clinical and radiological follow-up led to propose and confirm this diagnosis. Conclusion: Sometimes only longitudinal monitoring of patients with severe short stature evidence abnormalities suggesting a specific diagnosis. The right diagnosis results in suitable clinical care and genetic counseling to parents.