Aaron Tanner is a cherub-faced 4-year-old with a shock of white-blond hair and a ready smile. On the surface, the Brentwood boy looks like any other high-spirited, carefree preschooler, but it’s there that the similarities end.

Aaron was born with a heart that functions only on the right side. The condition kept the newborn in the hospital for six weeks before he was declared strong enough for his parents, Elizabeth and Kevin Tanner, to take him home.

But only a week later, the Tanners’ 2-year-old son Ethan suddenly developed flu-like symptoms. Unable to calm the agitated toddler, they rushed him to the hospital, where he died a few hours later from a rare heart disease called Pertrophic Cardiomypathy; a typically genetic disease that often strikes without warning.

The Tanners now face yet another heartbreaking challenge: last week, doctors discovered that Aaron –who has undergone seven open-heart surgeries since he was born – must now undergo a simultaneous heart and kidney transplant. Renal failure has placed too much stress on the boy’s heart, and without the rare double-transplant surgery, Aaron’s chances of survival are low.

“Aaron is currently at UCSF undergoing tests as everyone just tries to figure out what they are up against,” said Laura Page, executive director of Kids Helping Kids, who recently heard of the Tanners’ plight. “This surgery is so rare that they have teams within teams of doctors working on this. We’re just trying to get the word out and do what we can to help.”

Help will be coming in part through a fundraiser, to be held sometime next month, that Page is organizing. According to Page, the Tanners’ medical bills are stacking up, and because of the debt they incurred with the death of Ethan, the family is facing foreclosure on their home.

“Aaron takes eight different medications a day to regulate his heart and blood pressure, and to prevent water from building up around his heart,” said Page in a recent e-mail. “Just one (of the medications) costs $7,000 a month. They have a cap on their insurance, which they are dangerously close to (before this recent hospital stay and proposed surgery). They really need our prayers and big miracles.”

Aaron and his mom are expected to remain at UCSF for the next few weeks as doctors develop a plan and Aaron undergoes kidney dialysis. He will also be given a medication designed to ease the blood flow and keep his blood pressure in check.

Despite her son’s dire situation, Elizabeth remains strong and optimistic.

“Aaron is in good spirits, as always,” she wrote in a blog earlier this week. “He is a bit sleepy, but is still able to give the staff a run for their money. We are waiting and praying. I can’t thank everyone enough for their support and prayers, blogs and notes of love and encouragement. It feels like our whole community is really pulling for us and I know God hears our prayers; you can feel it, it’s so evident in all that is happening.”

For those able to help the Tanner family, a few options are available: a fund has been set up at the Bank of Agriculture on Balfour Road in Brentwood; you may donate online at the Network for Good Web site,www.networkforgood.org/donation/expressdonation.aspx?orgid2=208836568 and type “Aaron Tanner” in the donation field; and to help with the September fundraiser, call Laura Page at 925-759-4806.