Severe Short Stature and Endogenous Growth Hormone Resistance in Twin Brothers Without Growth Hormone Gene Mutations

Abstract Objectives To describe the metabolic and endocrine features of a patient with Barth syndrome who showed evidence of growth hormone resistance. Case presentation A male proband deteriorated rapidly with lactic acidosis after a circumcision at age three weeks and was found to have severe dilated cardiomyopathy. A cardiomyopathy gene panel led to the diagnosis of TAZ-deficiency Barth syndrome. He subsequently experienced hypotonia and gross motor delay, feeding difficulties for the first four years, constitutional growth delay and one episode of ketotic hypoglycaemia. Cardiomyopathy resolved on oral anti-failure therapy by age three years. He had a hormonal pattern of growth hormone resistance, and growth hormone treatment was considered, however height velocity improved spontaneously after age 3½ years. He also had biochemical primary hypothyroidism. Conclusions With careful metabolic management with l-arginine supplementation, overnight corn starch, and a prescribed exercise program, our patient’s strength, endurance, level of physical activity and body composition improved significantly by age six years.

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Mutations of uncertain significance in heterozygous variants as a possible cause of severe short stature: a case report

Molecular and Cellular Pediatrics ◽

10.1186/s40348-020-00104-6 ◽

2020 ◽

Vol 7 (1) ◽

Author(s):

Nami Mohammadian Khonsari ◽

Sahar Mohammad Poor Nami ◽

Benyamin Hakak-Zargar ◽

Tessa Voth

Keyword(s):

Growth Hormone ◽

Short Stature ◽

Hormone Receptors ◽

Bone Growth ◽

Synergistic Effects ◽

Signs And Symptoms ◽

Bone Age ◽

Pathogenic Mutation ◽

Paracrine Factors ◽

Severe Short Stature

Abstract Background Linear bone growth is achieved by the division of chondrocytes at the growth plate and is regulated by endocrine and paracrine factors such as growth hormone. Mutations that negatively affect chondrogenesis can be a contributor to short stature. One such mutation can occur in the ACAN gene, causing short stature and advanced bone age. Similarly, mutations in growth hormone receptors (GHR) can lead to Laron syndrome (LS), one of the several disorders that are collectively called growth hormone insensitivity syndrome (GHI). Another example is Floating-Harbor syndrome (FHS), a rare autosomal dominant due to mutations in the SRCAP gene that can also result in short stature. Case presentation We report the case of a 6-year-old female with concomitant mutations in the three genes mentioned above. The mutations reported here were found on genetic studies and are usually benign, causing a variant of undetermined significance. However, our patient’s phenotype could only be explained by the compounded effects of pathogenic mutations of these genes. Some of the same mutations were also found in the patient’s father and her paternal grandfather. Both also presented with short stature, though not to the same degree as our patient. While these mutations are often reported to be insignificant, they gave rise to severe short stature and a specific phenotype in the patient when presented together. We think that even though the GHI spectrum is inherited through an autosomal recessive pattern, the sum of these heterozygous mutations resulted in severe short stature despite the limited GHI seen in our patient, the father, and the grandfather, through a rare ACAN and SRCAP mutation that, to our knowledge, has not been previously reported as a pathogenic mutation in the literature. Conclusion We investigated the possible synergistic effects of these variations on exacerbation or masking of the signs and symptoms of GHI with the hope of providing a better understanding of these genes and their function through our rare case.

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