Severe Neonatal Cholestasis as an Early Presentation of McCune-Albright Syndrome

Neonatal cholestasis as the onset symptom of McCune-Albright syndrome: case reports and a literature review

Aim

This study aimed to summarize and show the characteristics and evolutionary process of neonatal cholestasis caused by McCune-Albright syndrome (MAS), as neonatal cholestasis may be the initial manifestation of MAS before other classic clinical features appear.

Methods

The clinical characteristics, treatment methods, and outcomes of three neonatal cholestasis cases caused by MAS in our center were retrospectively studied. In addition, all the reported cases of MAS combined with cholestasis were reviewed and summarized to show the cholestatic features in them.

Results

We have confirmed three MAS cases in our center, presenting onset symptoms of jaundice, pale stool, and neonatal cholestasis soon after birth. The cholestasis subsided spontaneously at around the sixth month. The literature review showed that the levels of total bilirubin, conjugated bilirubin, ALT, AST, and GGT in neonatal MAS cholestasis cases were 207 μmol/L (range 65-445 μmol/L), 162 μmol/L (range 46-412 μmol/L), 821 U/L (range 85-3,597 U/L), 532 U/L (range 127-3,633 U/L), and 244 U/L (range 79-3,800 U/L), respectively. Liver histology showed canalicular and hepatocellular cholestasis, giant hepatic cell transformation, and bile paucity. Extrahepatic manifestations such as café-au-lait pigmented skin lesions, Cushing's syndrome, hyperthyroidism, renal tubular dysfunction, and skeletal abnormalities could occur simultaneously when jaundice occurred. GNAS mutations had a high positive rate (83.3%-100%) in liver tissue with cholestasis. Neonatal cholestasis caused by MAS could be self-resolved, but hepatic lesions persist and have malignant potential.

Conclusion

MAS can be one of the causes of neonatal cholestasis, which may be the first manifestation of the disease. Extrahepatic coexisting symptoms of MAS and liver histology can help to distinguish MAS from other etiology of cholestasis. Detecting GNAS mutations in liver tissue may shorten diagnostic time and is of particular interest in the partial and atypical forms of MAS with neonatal cholestasis. Neonatal cholestasis in children with MAS can self-resolve, but liver dysfunction and malignant lesions persist.

The longest reported survival of a child with McCune-Albright syndrome and a severe early presenting phenotype consisting of neonatal cushing syndrome, cardiac and liver diseases

Neonatal cushing syndrome (NCS) is a rare disease that results from prolonged exposure to high cortisol levels. McCune-Albright syndrome (MAS) is an exceedingly rare genetic disorder characterized by cafe-au-lait skin spots, bone fibrous dysplasia and multiple endocrinopathies. We describe a case of a premature neonate with Intrauterine Growth Retardation who presented with hypercortisolemia, neonatal transaminitis and cardiac dysfunction. Further evaluation revealed significant bilateral adrenal hyperplasia leading to the diagnosis of NCS as part of MAS. Despite maximum medical therapy, including metyrapone, the baby's refractory hypertension, hyperglycemia and persistent failure to thrive (weight of 1.4 kg at corrected age 38 weeks) necessitated bilateral adrenalectomy. This case did not initially demonstrate the classic MAS triad, notably, the absence of skeletal manifestations. There has been no previous description of a baby who has had all the early life-threatening features present and survived beyond 18 months. This case highlights the severity of the phenotype and the challenges involved in diagnosing and treating NCS and MAS in neonates.

Neonatal cholestasis can be the first symptom of McCune–Albright syndrome: A case report

BACKGROUND

McCune–Albright syndrome (MAS) is caused by postzygotic somatic mutations of the GNAS gene. It is characterized by the clinical triad of fibrous dysplasia, café-au-lait skin spots, and endocrinological dysfunction. Myriad complications in MAS, including hepatobiliary manifestations, are also reported.

CASE SUMMARY

This is a case of a 4-year-old boy who presented with MAS with neonatal cholestasis. He was suspected to have Alagille syndrome due to neonatal cholestasis with intrahepatic bile duct paucity in liver biopsy, peripheral pulmonary artery stenosis, and renal tubular dysfunction. By the age of 2 years, his cholestatic liver injury gradually improved, but he had repeated left femoral fractures. He did not exhibit endocrinological abnormality or café-au-lait skin spots. However, MAS was suspected due to fibrous dysplasia at the age of 4 years. No mutation was identified in the GNAS gene in the DNA isolated from the peripheral blood, but an activating point mutation (c.601C>T, p.Arg201Cys) was observed in the DNA extracted from the affected bone tissue and that extracted from the formalin-fixed paraffin-embedded liver tissue, which was obtained at the age of 1 mo.

CONCLUSION

MAS should be considered as a differential diagnosis for transient cholestasis in infancy.

Neonatal McCune-Albright Syndrome: A Unique Syndromic Profile With an Unfavorable Outcome

Somatic gain‐of‐function mutations of GNAS cause a spectrum of clinical phenotypes, ranging from McCune‐Albright syndrome (MAS) to isolated disease of bone, endocrine glands, and more rarely, other organs. In MAS, a syndrome classically characterized by polyostotic fibrous dysplasia (FD), café‐au‐lait (CAL) skin spots, and precocious puberty, the heterogenity of organ involvement, age of onset, and clinical severity of the disease are thought to reflect the variable size and the random distribution of the mutated cell clone arising from the postzygotic mutation. We report a case of neonatal MAS with hypercortisolism and cholestatic hepatobiliary dysfunction in which bone changes indirectly emanating from the disease genotype, and distinct from FD, led to a fatal outcome. Pulmonary embolism of marrow and bone fragments secondary to rib fractures was the immediate cause of death. Ribs, and all other skeletal segments, were free of changes of typical FD and fractures appeared to be the result of a mild‐to‐moderate degree of osteopenia. The mutated allele was abundant in the adrenal glands and liver, but not in skin, muscle, and fractured ribs, where it could only be demonstrated using a much more sensitive PNA hybridization probe‐based FRET (Förster resonance energy transfer) technique. Histologically, bilateral adrenal hyperplasia and cholestatic disease matched the abundant disease genotype in the adrenals and liver. Based on this case and other sporadic reports, it appears that gain‐of‐function mutations of GNAS underlie a unique syndromic profile in neonates characterized by CAL skin spots, hypercortisolism, hyperthyroidism, hepatic and cardiac dysfunction, and an absence (or latency) of FD, often with a lethal outcome. Taken together, our and previous cases highlight the phenotypic severity and the diagnostic and therapeutic challenges of MAS in neonates. Furthermore, our case specifically points out how secondary bone changes, unrelated to the direct impact of the mutation, may contribute to the unfavorable outcome of very early‐onset MAS. © 2018 The Authors JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.