Introduction
Mulvihill-Smith syndrome is a rare condition that is characterized by premature aging, short stature, and multiple pigmented nevi. Other consistent clinical findings include lack of facial subcutaneous fat, microcephaly, sensorineural hearing loss, and intellectual disability. Immunodeficiency has been reported is some patients. Reported additional findings in adulthood include tumor development, sleep disorder with severe insomnia, and cognitive decline. The diagnosis is clinical as the genetic etiology of the condition has yet to be identified.

Case Presentation
The patient is a 13 year old male with clinical findings of Mulvihill-Smith syndrome. Overall growth is suboptimal (height -4.7 SD, weight -3.8 SD, head circumference -4.7 SD). There are numerous and evolving nevi of the entire body including the sclera and palms.  He has unilateral sensorineural hearing loss. Cognitive skills are consistent with intellectual disability and there is concern for declining verbal skills.  Facial features are distinctive (hypertelorism, low and broad nasal bridge with small nasal tip, retrognathia, overbite and overjet with prominent and discolored maxillary central incisors). His physical appearance dissimilar to his family and reminiscent of previously reported people with Mulvihill-Smith syndrome.

Additional findings include diabetes mellitus, severe hyponatremia noted during a hospital admission for diabetes management, hypocalcemia, vitamin D deficiency, severe hepatic cysts and nodules, history of splenectomy due to splenomegaly with cyst, cryptorchidism, high pitched voice, and joint restriction of the knees and elbows.

Family history is significant for nonconsanguineous parents with advanced paternal and maternal ages at the time of his birth (48 and 42 respectively). Three older siblings and their children are in good health.

Diagnostic Workup
The patient has a normal male karyotype (46,XY). Molecular genetic testing has not been obtained. Using OMIM and comparison with previously reported cases in the medical literature review, we arrived at the clinical diagnosis of Mulvihill-Smith syndrome.

Treatment and Management
Currently, his medical care is primarily driven by diabetes management and electrolyte abnormalities as they arise.

Outcome and Follow-Up
Given our clinical diagnosis of Mulvihill-Smith syndrome, we can prepare the medical team and family for anticipated medical issues as he ages. This will allow for appropriate surveillance for tumors and for proactive involvement of appropriate medical specialists.

Discussion
Mulvihill-Smith syndrome is a rare and under recognized genetic condition. The diagnosis remains solely clinical as a genetic etiology has yet to be identified. This patient adds to the limited information regarding the clinical findings, developmental issues, and evolving health issues associated with the condition.

Conclusion
Given the advanced paternal age, we hypothesize that Mulvihill-Smith syndrome is due to a de novo autosomal dominant condition. With his intact family structure, this patient would be an excellent candidate for research molecular genetic testing in hopes of identifying the genetic etiology of Mulvihill-Smith syndrome.