Multisystem obstruction with cholestasis, pigmentary retinopathy, and cleft palate: a new syndrome?

MED12-related Hardikar syndrome: Two additional cases and novel phenotypic features

Hardikar syndrome (HS) is a MED12‐related ultra‐rare multiple congenital malformation syndrome known to affect the gastrointestinal, cardiac, and genitourinary systems among other features including cleft lip/palate and pigmentary retinopathy. Only 10 patients affected with HS have been previously described in literature, of which seven were molecularly confirmed. We report a 20‐year‐old and a 13‐month‐old patient with HS diagnosed by exome sequencing bringing the total number of clinically diagnosed cases to 12 and MED12 associated to 9. We describe previously unreported molecular and clinical findings associated with HS and review all reported cases to permit prompt diagnosis, appropriate management, and genetic counseling of HS patients.

De novo loss-of-function variants in X-linked MED12 are associated with Hardikar syndrome in females

PURPOSE

Hardikar syndrome (MIM 612726) is a rare multiple congenital anomaly syndrome characterized by facial clefting, pigmentary retinopathy, biliary anomalies, and intestinal malrotation, but with preserved cognition. Only four patients have been reported previously, and none had a molecular diagnosis. Our objective was to identify the genetic basis of Hardikar syndrome (HS) and expand the phenotypic spectrum of this disorder.

METHODS

We performed exome sequencing on two previously reported and five unpublished female patients with a clinical diagnosis of HS. X-chromosome inactivation (XCI) studies were also performed.

RESULTS

We report clinical features of HS with previously undescribed phenotypes, including a fatal unprovoked intracranial hemorrhage at age 21. We additionally report the discovery of de novo pathogenic nonsense and frameshift variants in MED12 in these seven individuals and evidence of extremely skewed XCI in all patients with informative testing.

CONCLUSION

Pathogenic missense variants in the X-chromosome gene MED12 have previously been associated with Opitz-Kaveggia syndrome, Lujan syndrome, Ohdo syndrome, and nonsyndromic intellectual disability, primarily in males. We propose a fifth, female-specific phenotype for MED12, and suggest that nonsense and frameshift loss-of-function MED12 variants in females cause HS. This expands the MED12-associated phenotype in females beyond intellectual disability.

Aortic coarctation and carotid artery aneurysm in a patient with Hardikar syndrome: Cardiovascular implications for affected individuals

Hardikar syndrome is a multiple congenital anomaly syndrome first characterized in 1992 by Hardikar et al. to describe two individuals with cholestasis, cleft lip/palate, retinal pigmentation, intestinal abnormalities, and genitourinary anomalies. Between 1992 and 2002, four individuals with Hardikar syndrome were reported in the literature. The fourth individual [Maluf et al. (2002), Transplantation 74:1058-1061; Poley and Proud (2008) Am J Med Genet Part A 146A:2473-2479], who had progressive cholestatic liver disease ultimately requiring liver transplantation, has continued to be followed at our institution. Recently, at the age of 14 years, during an evaluation for refractory hypertension, she was found to have developed coarctation of the aorta that was treated with aortic angioplasty and stenting, dramatically improving her hypertension. Further vascular investigation also revealed a small aneurysm of her carotid artery requiring neurosurgical evaluation and anticoagulant therapy. To our knowledge, these vascular anomalies have not been reported in Hardikar syndrome and the high association of congenital heart disease in the individuals with Hardikar syndrome has not been further addressed. Herein, we discuss this additional clinical information, speculate briefly on possible molecular etiologies, and discuss potential cardiac surveillance recommendations. We hope that broadening the known phenotype of this very rare disorder will further aid clinicians in their management and surveillance for these individuals.

Hardikar syndrome: new features

Hardikar syndrome (HS) is a disorder of multiple anomalies predominantly characterized by cleft lip/palate, liver and biliary tract disease, intestinal malrotation, obstructive uropathy, and retinopathy. To date, three patients have been reported with the unusual constellation of chronic liver/biliary tract disease and obvious defects in organogenesis [Hardikar et al. (1992): Am J Med Genet 44: 13-17; Cools and Jaeken (1997): Am J Med Genet 71: 472-474]. With this report, we add another patient with this syndrome. New features, hitherto not reported, were vaginal atresia, a type 1 choledochal cyst and, owing to the progressive nature of the liver disease, the need for liver transplantation. It is intriguing to speculate, that HS could be genetically related to Alagille syndrome (AS), since both conditions share an unusual number of phenotypic abnormalities.

Kabuki make-up syndrome

Kabuki make-up syndrome is a rare disorder characterized by mental retardation, postnatal dwarfism and peculiar facies. This condition is believed to be common in Japan, but has been reported from other parts of the world. The authors report a case of this syndrome in an eight-year-old girl, with the characteristic findings from India.

Hardikar syndrome: a case requiring liver transplantation

We report the case of a girl with Hardikar syndrome who underwent living-donor liver transplantation at 2 years of age. This disease, described in 1992, includes a constellation of abnormalities, such as cleft lip and palate, pigmentary retinopathy, and multiple tubular stenoses (e.g., bile ducts, ureters). Other system involvement is variable. Rotation anomalies of the gut and cardiac abnormalities are frequently present. Pathogenesis remains obscure. Our patient was delivered at 33 weeks of gestation by cesarean section, and was jaundiced, with low birth weight and height. On day 5 after birth, the patient underwent Ladd's surgery for intestinal malrotation. One month later, she developed pyelonephritis and urosepsis. She remained jaundiced and a liver biopsy revealed cirrhosis with regenerating nodules, portal chronic inflammation with bile duct proliferation, and lobular cholestasis. The patient underwent several corrective operations, and at 12 months of age she was diagnosed with Hardikar syndrome. She failed to thrive and had progressive cholestasis and jaundice, coagulation disorders, bilateral ureterostomies, repetitive urinary tract infections, bilateral cleft lip and palate, retinopathy, and gut malrotation. She received a liver transplant at 24 months of age from a living donor. She has had an excellent clinical outcome in liver function without further decline of growth and development.

Kabuki syndrome: a review study of three hundred patients

The Kabuki (make-up) syndrome identified in 1981 has been reported in more than three hundred patients. Typical findings include mild to moderate mental retardation, fetal pads, cleft palate, and characteristic facies with long palpebral fissures, everted lower lateral eyelids and arched eyebrows. Postnatal growth retardation, skeletal and visceral anomalies are present in a large percentage of patients. We review here the characteristics of this peculiar syndrome in three hundred patients.

Hardikar syndrome: a new syndrome with cleft lip/palate, pigmentary retinopathy and cholestasis

We present a child with a remarkable constellation of abnormalities comprising cleft lip and palate, pigmentary retinopathy, hydronephrosis, malrotation of the gut and obstructive liver disease. This patient, together with two other reported cases, seems to represent a new syndrome with some similarities to the Kabuki syndrome.